Xilinx DS438 OPB Multi Channel HDLC Interface … Multi Channel HDLC Interface (v2.01a) DS438...

- THIS IS A DISCONTINUED IP CORE -

0

OPB Multi Channel HDLC Interface (v2.01a)

DS438 December 1, 2005 0 0 Product Specification

IntroductionThis specification defines the architecture and interface requirements to this module, including registers that the user must initialize for proper operation. The Xilinx HDLC design allows the customer to tailor the HDLC to suit their application by setting certain parameters to enable/disable features. The parameterizable features of the design are discussed in HDLC Design Parameters.

Features Support for one to eight independent full duplex

HDLC channels.

Each independent channel may have 1 to 32 TDM sub-channels.

Receive FIFO buffer of selectable depth.

Transmit FIFO buffer of selectable depth.

Support for Packets larger than FIFO depth.

Selectable 8/16 bit address receive address detection.

Selectable receive frame address discard.

Selectable receive broadcast address detection. Broadcast address = 0xFF.

Selectable FCS 16 bit (CRC-CCITT) or 32 bit (CRC-32)

CRC error counter, with rollover interrupt

Aborted frame counter, with rollover interrupt

Multiple Events/Interrupts including:

- Rx FCS error interrupt

- Rx frame alignment error interrupt

- Memory buffer overrun/underrun interrupts

LogiCORE Facts

Core Specifics

Supported Device Family

QPro-R Virtex-II, QPro Virtex-II, Spartan-3, Spartan-3E, Virtex, Virtex-II,

Virtex-II Pro, Virtex-4

Resources Used (minimum settings)

I/O LUTs FFsBlock RAMs

6 1203 604 2

Version of Core opb_hdlc_v2_01_a

Provided with Core

Documentation Product Specification

Design File Formats VHDL

Constraints File N/A

Verification N/A

Instantiation Template

N/A

Reference Designs & application notes

N/A

Additional Items N/A

Design Tool Requirements

Xilinx Implementation Tools

ISE 6.1i or later

with latest EDK

Verification ModelSim PE 5.7d

Simulation ModelSim PE 5.7d

Synthesis XST - ISE 6.1i

Support

Support provided by Xilinx, Inc.

DS438 December 1, 2005 www.xilinx.com 1Product Specification

2005 Xilinx, Inc. All rights reserved. All Xilinx trademarks, registered trademarks, patents, and further disclaimers are as listed at http://www.xilinx.com/legal.htm. All other trademarks and registered trademarks are the property of their respective owners. All specifications are subject to change without notice.NOTICE OF DISCLAIMER: Xilinx is providing this design, code, or information "as is." By providing the design, code, or information as one possible implementation of this feature, application, or standard, Xilinx makes no representation that this implementation is free from any claims of infringement. You are responsible for obtaining any rights you may require for your implemen-tation. Xilinx expressly disclaims any warranty whatsoever with respect to the adequacy of the implementation, including but not limited to any warranties or representations that this imple-mentation is free from claims of infringement and any implied warranties of merchantability or fitness for a particular purpose.

http://www.xilinx.comhttp:www.xilinx.com/legal.htmhttp://www.xilinx.com/legal.htmhttp://www.xilinx.com/legal.htm


2


Features (contd) Tx frame abort control

Memory mapped direct I/O interface to registers and memory buffers.

Flag sharing between back to back frames

Independent Rx and Tx data rates for each physical channel. The OPB_CLK must be at least 1.1x higher frequency than the Rx or Tx data rate when a single sub channel is selected or 3x higher when more than one sub channel is selected.

Evaluation VersionThe HDLC LogiCORE is delivered with a hardware evaluation license. When programmed into a Xilinx device, the core will function in hardware for about 8 hours at the typical frequency of operation. To use the HDLC LogiCORE without this timeout limitation, a full license must be purchased.

HDLC Protocol

HDLC exists in layer 2 of the OSI model which is the data link layer. HDLC uses transparency to ensure that the bit pattern of the delimiter flag does not occur in the fields between flags. The HDLC frame is synchronous and therefore relies on the physical layer to provide a method of clocking and synchronizing the transmission and reception of frames. The control and data are not used by the hardware for any type of configuration or control.

An example of an HDLC frame that may contain no address or an 8-bit or 16-bit address is shown below.

Figure 1: HDLC Frame Example with no Address, 8-bit, or 16-bit Address

Figure Top x-ref 1

OpeningFlag

01111110

Address(if used)8 bits or 16 bits

ControlData

8*n-bits

FCSCRC - CCITTor CRC - 32

ClosingFlag

01111110

hdlc_frame_none_8or16_bit_addr.eps

Transparency

Transparency is the process of preventing the Flag pattern from occurring in the address, data or FCS fields. A zero bit is inserted, by the transmitter, any time a sequence of five consecutive ones has occurred. This will make the HDLC transparent to any type of data because any bit stream may exist between the opening and closing Flags. The receiver must remove the zero bit insertion to recover the original data sent.

An original bit pattern of:

11111110 01111111 01111101

Will become after bit stuffing:

111110110 011111011 011111001

www.xilinx.com DS438 December 1, 2005Product Specification

http://www.xilinx.com


DS438 DecProduct Sp


Flag Field

Each frame starts and stops with the flag sequence as shown above. The 0x7E flag is used for frame synchronization. Only one flag sequence is required to be between frames. The closing flag shown above could also be the opening flag for the next frame. A back to back flag sequence is an empty frame.

An empty frame is not counted as an FCS error. The flag bytes are not stored in the receive buffer. When the transmitter is enabled and there is no data to transmit, the transmitter will continuously send flags.

Address Field

The address field is typically 8 bits, however it can be 0 bits in a point to point or extended to 16 bits. The address identifies the secondary station that will receive the frame or transmit the frame. An address of all ones, 0xFF, is interpreted as an all stations address. This allows a broadcast frame to be received by all secondary stations.

Control Field

The 8 or 16 bit control field provides a flow control number and defines the frame type (control or data). The exact use and structure of this field depends upon the protocol using the frame. An integer number, including 0, of octets must be contained in this field to prevent an alignment error.

Information/Data Field

Data is transmitted in the information/data field, which can vary in length depending upon the protocol using the frame. An integer number, including 0, of octets must be contained in this field to prevent an alignment error.

Frame Check Sequence (FCS) Field

Error Control is implemented by appending a cyclic redundancy check (CRC) to the frame, which is 16 bits (CRC-CCITT) or 32 bits (CRC-32) long. The flag bits are not used in calculating the CRC. The FCS is stored in the receive buffer.

HDLC Design ParametersThe OPB Multi Channel HDLC design is user configurable via a set of design parameters implemented as VHDL input generics. The generics for the OPB Multi Channel HDLC are listed in Table 1.

Table 1: HDLC Design Parameters

GenericFeature /

DescriptionParameter Name

Allowable Values

Default Value

VHDL Type

HDLC Features

G1Number of Physical HDLC Channels

C_NUM_CHANNELS 1 - 8 1 Integer

G2Number of TDM sub-channels per Physical Channel 0

C_NUM_SUB_CHANNELS_0 0 - 32 1 Integer





ember 1, 2005 www.xilinx.com 3ecification



4












OPB/IPIF Interface

G20OPB Clock period in pico-seconds

C_OPB_CLK_PERIOD_PS

The period of the OPB bus

clock in pico-seconds

10000 Integer

G21 Device Block ID C_DEV_BLK_ID See note 5. 0 Integer

G22Module Identification Register Enable

C_DEV_MIR_ENABLE See note 5. 0 Integer

G23 OPB High Address C_HIGHADDR

Address range must

be a power of 2 and can

vary with the number of

HDLC channels(4)

None(2,3)std_logic_vector

G24Location of the first IPIF register.

C_BASEADDRValid Address

Range(4)None(2,3)

std_logic_vector

G25 OPB Address Bus Width C_OPB_AWIDTH 32 32 integer

G26 OPB Data Bus Width C_OPB_DWIDTH 32 32 integer

G27FPGA Device Family Type

C_FAMILY

spartan2

spartan2e

spartan3virtex

virtexe

virtex2

virtex2pqvirtex2

qrvirtex2

virtex2p string

Table 1: HDLC Design Parameters (Contd)

GenericFeature /


Allowable Values

Default Value

VHDL Type




DS438 DecProduct Sp


G28 DMA Present C_DMA_PRESENT(2)

1 = No DMA is used and

normal IPIF is used

2 = DMA with Scatter/Gather is used and normal IPIF

1 integer

Channel FIFO

G30Transmit FIFO Depth in bytes(6)

C_TX_MEM_DEPTH_0(6, 7, 8, 9)

1 BRAM Minimum(8)

32 BRAMs Maximum(9)

2048 Integer

G31Receive FIFO Memory Depth in bytes(7)

C_RX_MEM_DEPTH_0(6, 7, 8, 9)

1 BRAM Minimum(8)

32 BRAMs Maximum(9)

2048 Integer


C_TX_MEM_DEPTH_1(6, 7, 8, 9)

1 BRAM Minimum(8)

32 BRAMs Maximum(9)

0 Integer

G33Receive Buffer Memory Depth in bytes(7)

C_RX_MEM_DEPTH_1(6, 7, 8, 9)

1 BRAM Minimum(8)

32 BRAMs Maximum(9)

0 Integer


C_TX_MEM_DEPTH_2(6, 7, 8, 9)

1 BRAM Minimum(8)

32 BRAMs Maximum(9)

0 Integer


C_RX_MEM_DEPTH_2(6, 7, 8, 9)

1 BRAM Minimum(8)

32 BRAMs Maximum(9)

0 Integer


C_TX_MEM_DEPTH_3(6, 7, 8, 9)

1 BRAM Minimum(8)

32 BRAMs Maximum(9)

0 Integer


C_RX_MEM_DEPTH_3(6, 7, 8, 9)

1 BRAM Minimum(8)

32 BRAMs Maximum(9)

0 Integer


C_TX_MEM_DEPTH_4(6, 7, 8, 9)

1 BRAM Minimum(8)

32 BRAMs Maximum(9)

0 Integer


GenericFeature /


Allowable Values

Default Value

VHDL Type




6



C_RX_MEM_DEPTH_4(6, 7, 8, 9)

1 BRAM Minimum(8)

32 BRAMs Maximum(9)

0 Integer


C_TX_MEM_DEPTH_5(6, 7, 8, 9)

1 BRAM Minimum(8)

32 BRAMs Maximum(9)

0 Integer


C_RX_MEM_DEPTH_5(6, 7, 8, 9)

1 BRAM Minimum(8)

32 BRAMs Maximum(9)

0 Integer


C_TX_MEM_DEPTH_6(6, 7, 8, 9)

1 BRAM Minimum(8)

32 BRAMs Maximum(9)

0 Integer


C_RX_MEM_DEPTH_6(6, 7, 8, 9)

1 BRAM Minimum(8)

32 BRAMs Maximum(9)

0 Integer


C_TX_MEM_DEPTH_7(6, 7, 8, 9)

1 BRAM Minimum(8)

32 BRAMs Maximum(9)

0 Integer


C_RX_MEM_DEPTH_7(6, 7, 8, 9)

1 BRAM Minimum(8)

32 BRAMs Maximum(9)

0 Integer

HDLC I/O

G90Number of bits required to encode the number of sub-channels

C_NUM_SUB_CHANNEL_BITS_0

1 - log2(C_NUM_SUB_CHAN

NELS(0))

1 integer


C_NUM_SUB_CHANNEL _BITS_1


NELS(1))

0 integer


C_NUM_SUB_CHANNEL_ BITS_2


NELS(2))

0 integer




NELS(3))

0 integer


GenericFeature /


Allowable Values

Default Value

VHDL Type




DS438 DecProduct Sp


Allowable Parameter Combinations

The address range specified by C_BASEADDR and C_HIGHADDR must be a power of 2, and C_HIGHADDR must be at least 0x3FFFF. For example, if C_BASEADDR = 0x60100000 C_HIGHADDR must be at least = 0x6013FFFF.




NELS(4))

0 integer




NELS(5))

0 integer




NELS(6))

0 integer




NELS(7))

0 integer

Notes: 1. Each physical channel may have an independent serial transmit and serial receive clock inputs.2. Anytime DMA is present, interrupt coalescing is enabled3. For example, C_BASEADDR = 0x60100000, C_HIGHADDR = 0x6013FFFF 4. Address range specified by C_BASEADDR and C_HIGHADDR must be at least 0X3FFFF and must be a

power of 2. C_BASEADDR must be a multiple of the range, where the range is C_HIGHADDR - C_BASEADDR +1.

5. For a Virtex-II Pro a single BRAM is 2048 bytes and 32 Brams is 65536 bytes. 6. Both the receive and transmit FIFO is equally divided in powers of 2 among all the sub-channels.7. For example a transmit FIFO of 2048 bytes (1 BRAM) and 24 sub-channels would cause a transmit FIFO depth

of 60 bytes for each individual sub-channel, (2048/(32)) - 4. 2048 is the memory depth, 32 is the next power of two equal to or larger than 24, and 4 bytes are used by each sub channel in the FIFO to maintain status.

8. It is possible to specify a FIFO depth smaller than 1 BRAM, however 1 BRAM will be used and the unused memory is not available.

9. The maximum size for a sub channel FIFO is 16384 bytes. If two sub channels are specified on a single physical channel, the maximum FIFO size is 32768. If three sub channels are specified on a single physical channel the maximum FIFO depth is 49152.


GenericFeature /


Allowable Values

Default Value

VHDL Type




8


HDLC I/O SignalsThe I/O signals for the HDLC are listed in Table 2.

Table 2: HDLC I/O Signals

Port Signal Name Interface I/OInitial State

Description

HDLC Signals

P1 RXD(0 to C_NUM_CHANNELS - 1) System I HDLC Serial Data Input

P2 TXD(0 to C_NUM_CHANNELS - 1) System O 0 HDLC Serial Data Output

P3 RXden(0 to C_NUM_CHANNELS - 1) 1 System I HDLC RX data enable

P4 TXden(0 to C_NUM_CHANNELS - 1) 1 System I HDLC TX data enable

P5 RXCLK(0 to C_NUM_CHANNELS - 1) 1 System IHDLC Serial Receive Clock Input

P6 TXCLK(0 to C_NUM_CHANNELS - 1) 1 System IHDLC Serial Transmit Clock Input

P7

Rx_Chnl_Sel(0 to C_NUM_SUB_CHANNEL_BITS_0 + C_NUM_SUB_CHANNEL_BITS_1 + C_NUM_SUB_CHANNEL_BITS_2 + C_NUM_SUB_CHANNEL_BITS_3 + C_NUM_SUB_CHANNEL_BITS_4 + C_NUM_SUB_CHANNEL_BITS_5 + C_NUM_SUB_CHANNEL_BITS_6 + C_NUM_SUB_CHANNEL_BITS_7) 2, 3

System IHDLC receive sub-channel select input

P8

Tx_Chnl_Sel(0 to C_NUM_SUB_CHANNEL_BITS_0 + C_NUM_SUB_CHANNEL_BITS_1 + C_NUM_SUB_CHANNEL_BITS_2 + C_NUM_SUB_CHANNEL_BITS_3 + C_NUM_SUB_CHANNEL_BITS_4 + C_NUM_SUB_CHANNEL_BITS_5 + C_NUM_SUB_CHANNEL_BITS_6 + C_NUM_SUB_CHANNEL_BITS_7) 2, 3

System O 0HDLC transmit sub-channel select output

OPB Signals

P17 Sln_DBus(0:C_OPB_DWIDTH-1) IPIF O 0 HDLC output data bus

P18 Sln_xferAck IPIF O 0 HDLC transfer acknowledge

P19 Sln_Retry IPIF O 0 HDLC retry

P20 Sln_ToutSup IPIF O 0 HDLC timeout suppress

P21 Sln_ErrAck IPIF O 0 HDLC error acknowledge

P22 OPB_ABus(0:C_OPB_AWIDTH-1) IPIF I OPB address bus

P23 OPB_BE(0:C_OPB_DWIDTH/8-1) IPIF I OPB byte enables

P24 OPB_DBus(0:C_OPB_DWIDTH-1) IPIF I OPB data bus

P25 OPB_RNW IPIF IRead not Write (OR of all master RNW signals)




DS438 DecProduct Sp


HDLC Port DependenciesThe width of some of the HDLC signals depends on parameters selected in the design. The dependencies between the HDLC design parameters and I/O signals are shown in Table 3.

P26 OPB_select IPIF IMaster has taken control of the bus (OR of all master selects)

P27 OPB_seqAddr IPIF I OPB sequential address

P28 OPB_errAck IPIF I OPB error acknowledge

P29 OPB_MGrant IPIF I OPB master bus grant

P30 OPB_retry IPIF I OPB retry

P31 OPB_timeout IPIF I OPB timeout error

P32 OPB_xferAck IPIF I OPB transfer acknowledge

P33 Mn_request IPIF O 0 HDLC master bus request

P34 Mn_busLock IPIF O 0HDLC master bus arbitration lock

P35 Mn_select IPIF O 0 HDLC master select

P36 Mn_RNW IPIF O 0 HDLC master Read not Write

P37 Mn_BE(0:C_OPB_DWIDTH/8-1) IPIF O 0 HDLC master byte enables

P38 Mn_seqAddr IPIF O 0HDLC master sequential address

P39 Mn_ABus(0:C_OPB_ABUS_WIDTH-1) IPIF O 0 HDLC master address bus

System

P40 OPB_Clk System I System clock

P41 OPB_Rst System I System Reset (active high)

P42 IP2INTC_Irpt System O System Interrupt

P43 Freeze System I System Freeze Input

Notes: 1. The OPB_CLK must be at least 1.1x faster than the Rx or Tx data rate for a physical channel with one sub

channel, the OPB_CLK must be at least 3x faster than Rx or Tx data rates for a physical channel with more than one sub channel. The Rx data rate is controlled by the RXCLK and RXden, the Tx data rate is controlled by TXCLK and TXden.

2. If a no TDM sub-channels exist on any of the physical channels then this signal is undefined, but the vector will exist and be of length one (0 to 0). If any of the physical channels have more than one TDM sub-channel then this vector will be the concatenation of all the physical channels. For example if physical channel one has 24 sub-channels and physical channel two has 32 sub-channels and physical channel three has two sub-channels, then the vector is divided as follows, (0 to 4) physical channel one, (5 to 9) physical channel two, (10) physical channel three.

3. This vector will always be one larger than necessary. The top bit is to be ignored.

Table 2: HDLC I/O Signals (Contd)

Port Signal Name Interface I/OInitial State

Description




10


Table 3: HDLC Parameter Port Dependencies

Generic or Port

Name Affects Depends Relationship Description

Design Parameters

G1 C_NUM_CHANNELSP1, P2, P3, P4, P5, P6

Specifies the number of physical channels

G2 C_NUM_SUB_CHANNELS_0 P7, P8Specifies the number of sub-channels for Physical Channel 0








G28 C_OPB_DWIDTHP17, P23, P24

Specifies the OPB Data Bus width

G27 C_OPB_AWIDTHP22, P39

Specifies the OPB Address Bus width

I/O Signals

P1 RXD(0 to C_NUM_CHANNELS - 1) G1Width varies with the number of channels.

P2 TXD(0 to C_NUM_CHANNELS - 1) G1Width varies with the number of channels.

P3 RXden(0 to C_NUM_CHANNELS - 1) G1Width varies with the number of channels.

P4 TXden(0 to C_NUM_CHANNELS - 1) G1Width varies with the number of channels.




DS438 DecProduct Sp


HDLC Register DescriptionsThe HDLC contains addressable registers for read/write operations as shown in Table 4, Table 5, Table 6, Table 7 and Table 9 The base address for these registers is set in the parameter C_BASEADDR. C_BASEADDR + 0x1000 represents the address of the first register in the HDLC - in this case, the HDLC Status FIFO (SF). The address of each register is then calculated by an offset to the base address plus the physical channel offset plus the sub-channel offset.

The registers in Table 4 are contained in the IPIF module and are included for completeness of this specification. Please refer to the Processor IP Reference Guide under Part 1: Embedded Processor IP, under IPIF, under OPB IPIF Architecture, under OPB IPIF Register Descriptions for a complete description of these registers.

P5RXCLK(0 to log2(C_NUM_CHANNELS) - 1)

G1Width varies with the number of channels.

P6TXCLK(0 to log2(C_NUM_CHANNELS) - 1)

G1Width varies with the number of channels.

P7

Rx_Chnl_Sel(0 to C_NUM_SUB_CHANNEL_BITS_0 + C_NUM_SUB_CHANNEL_BITS_1 + C_NUM_SUB_CHANNEL_BITS_2 + C_NUM_SUB_CHANNEL_BITS_3 + C_NUM_SUB_CHANNEL_BITS_4 + C_NUM_SUB_CHANNEL_BITS_5 + C_NUM_SUB_CHANNEL_BITS_6 + C_NUM_SUB_CHANNEL_BITS_7)

G1, G2Width varies with the number of channels. Width varies with the number of sub-channels.

P8

Tx_Chnl_Sel(0 to C_NUM_SUB_CHANNEL_BITS_0 + C_NUM_SUB_CHANNEL_BITS_1 + C_NUM_SUB_CHANNEL_BITS_2 + C_NUM_SUB_CHANNEL_BITS_3 + C_NUM_SUB_CHANNEL_BITS_4 + C_NUM_SUB_CHANNEL_BITS_5 + C_NUM_SUB_CHANNEL_BITS_6 + C_NUM_SUB_CHANNEL_BITS_7)

G1, G2Width varies with the number of channels. Width varies with the number of sub-channels.

P17 Sln_DBus(0:C_OPB_DWIDTH-1) G28 Width varies with the size of the OPB Data bus.

P22 OPB_ABus(0:C_OPB_AWIDTH-1) G27Width varies with the size of the OPB Address bus.

P23 OPB_BE(0:C_OPB_DWIDTH/8-1) G28Width varies with the size of the OPB Data bus.

P24 OPB_DBus(0:C_OPB_DWIDTH-1) G28Width varies with the size of the OPB Data bus.

P39M_ABus(0:C_OPB_ABUS_WIDTH-1)

G27Width varies with the size of the OPB Data bus.

Table 3: HDLC Parameter Port Dependencies (Contd)

Generic or Port

Name Affects Depends Relationship Description




12


IPIF Registers used by the HDLC

Table 4: HDLC IPIF Registers

Register Name OPB ADDRESS Access

Device Interrupt Status Register C_BASEADDR + 0x0000 Read/Write

Device Interrupt Pending Register C_BASEADDR + 0x0004 Read/Write

Device Interrupt Enable Register C_BASEADDR + 0x0008 Read/Write

Device Interrupt Identification Register C_BASEADDR + 0x0018 Read/Write

Device Global Interrupt Enable C_BASEADDR + 0x001C Read/Write

IP Interrupt Status Register C_BASEADDR + 0x0020 Read/Write

IP Interrupt Enable Register C_BASEADDR + 0x0028 Read/Write

Device Software Reset (write) Module Identification (read) Register

C_BASEADDR + 0x0040 Read/Write

DMA Module Identification Register(1) C_BASEADDR + 0x1010 Read

DMA Global CSR(1) C_BASEADDR + 0x1014 Read/Write

DMA Event FIFO(1) C_BASEADDR + 0x1018 Read

DMA Reserved for system(1,2) C_BASEADDR + dmasg_chan*0X20 + 0x10000 none

DMA Control Register(1,2) C_BASEADDR + dmasg_chan*0X20 + 0x10004 Read/Write

DMA Source Address(1,2) C_BASEADDR + dmasg_chan*0X20 + 0x10008 Read/Write

DMA Destination Address(1,2)C_BASEADDR + dmasg_chan*0X20 +

0x1000CRead/Write

DMA Length(1,2) C_BASEADDR + dmasg_chan*0X20 + 0x10010 Read/Write

DMA Status Register(1,2) C_BASEADDR + dmasg_chan*0X20 + 0x10014 Read

DMA Buffer Descriptor Address(1,2) C_BASEADDR + dmasg_chan*0X20 + 0x10018 Read/Write

DMA Software Control Register(1,2)C_BASEADDR + dmasg_chan*0X20 +

0x1001CRead/Write

Notes: 1. These registers are available only if C_DMA_PRESENT = 2.2. These 8 registers are repeated for every DMA channel. A DMA channel is a half duplex channel, so a single

channel HDLC which is full duplex contains 2 DMA channels one for Tx and one for Rx.

HDLC Registers

Table 5, Table 6, and Table 7 shows the HDLC registers and addresses, the physical channel offset, and the sub-channel offset. Table 8 and Table 9 show the address offsets for the channel FIFOs.

Table 5: HDLC Registers

Register Name OPB Address Access

Status FIFO (SF) C_BASEADDR + 0x1000 Read

Device Control Register (MSCR) C_BASEADDR + 0x1100 Read/Write

TX Event FIFO (TXEF) C_BASEADDR + 0x1104 Read

RX Event FIFO (RXEF) C_BASEADDR + 0x1108 Read




DS438 DecProduct Sp


Physical Channel 0 Control Register (PCCR(0)) C_BASEADDR + 0x1110 Read/Write

Number of Aborted Frames per physical channel 0 (ABRT(0)) C_BASEADDR + 0x1114 Read/Write

Number of CRC Errors per physical channel 0 (CRCE(0)) C_BASEADDR + 0x1118 Read/Write

Physical Channel 1 Control Register (PCCR(1))1 C_BASEADDR + 0x1120 Read/Write

Number of Aborted Frames per physical channel 1 (ABRT(1))1


Number of CRC Errors per physical channel 1 (CRCE(1))1 C_BASEADDR + 0x1128 Read/Write

























TX Sub channel Control (TXCR)(2)C_BASEADDR + Physical Offset(3) + Sub-Channel

Offset(4)Read/Write

RX Sub channel Control, Address (RXCA)(2)C_BASEADDR + Physical Offset(3) + Sub-Channel

Offset(4) + 0x800Read/Write

Table 5: HDLC Registers (Contd)





14


TX DATA FIFO STATUS (TXDFS)C_BASEADDR + FIFO

Offset(5) + FIFO Sub-channel Offset(6)

Read

TX DATA FIFO (TXDF)C_BASEADDR + FIFO

Offset(5) + FIFO Sub-channel Offset(6)

Write

RX DATA FIFO STATUS (RXDFS)C_BASEADDR + FIFO

Offset(5) + FIFO Sub-channel Offset(6) + 0x2000

Read

RX DATA FIFO (RXDF)C_BASEADDR + FIFO

Offset(5) + FIFO Sub-channel Offset(6) + 0x2004

Read

Notes: 1. The availability of these registers depends on C_NUM_CHANNELS.2. If more than one sub channel is specified these registers are stored in BRAM. After a reset the entire Tx and

Rx BRAM must be initialized to zeros. This includes all the address space between each control register.3. The Physical Offset values are listed in Table 6.4. The Sub-channel Offset values are listed in Table 7.5. The FIFO Offset values are listed in Table 8.6. The FIFO Sub-channel Offset values are listed in Table 9.

Table 6: HDLC Physical Channel Control Registers Offset Values

Register Name Offset Value

Physical Channel 0, Sub-Channel 0 0x18000


Physical Channel 2, Sub-Channel 0 0x1A000

Physical Channel 3, Sub-Channel 0 0x1B000

Physical Channel 4, Sub-Channel 0 0x1C000

Physical Channel 5, Sub-Channel 0 0x1D000

Physical Channel 6, Sub-Channel 0 0x1E000

Physical Channel 7, Sub-Channel 0 0x1F000

Table 7: HDLC Sub-channel Control Registers Offset Values


Sub-Channel 0 0x0000





Table 5: HDLC Registers (Contd)





DS438 DecProduct Sp


Sub-Channel 5 0x00A0

Sub-Channel 6 0x00C0

Sub-Channel 7 0x00E0

























Table 8: HDLC FIFO Offset Values





Table 7: HDLC Sub-channel Control Registers Offset Values (Contd)





16







Table 9: HDLC FIFO Sub Channel Offset Values


FIFO Sub-Channel 0 0x0000




















FIFO Sub-Channel 20 0x0A00

FIFO Sub-Channel 21 0x0A80

FIFO Sub-Channel 22 0x0B00

FIFO Sub-Channel 23 0x0B80

FIFO Sub-Channel 24 0x0C00

Table 8: HDLC FIFO Offset Values





DS438 DecProduct Sp


Address Bus Usage for Channel FIFOs

Figure 2: Address Bus Usage for Channel FIFOs

Figure Top x-ref 2

addr_bus_usage_channel_fifos.eps

0 13 14 17 18 27 2825 26 29 30 31

Device Address FIFO Sub-channel Tag(1)

FIFO Phy Channel Tag(0) Tag(2) Zero

Tag(3)

Tag Bits(0 to 3), Address bits(26 to 29)

Tag bits make use of the extra data bits that exist in a BRAM. By placing the tag bits in the address space, sixteen extra address ranges are used for each FIFO. This allows the processor to write 36 bits of data to each FIFO, 32 bits of data are written on the data bus as normal, then depending upon which address is written to the tag bits are set as shown in Table 10

FIFO Sub-Channel 25 0x0C80

FIFO Sub-Channel 26 0x0D00

FIFO Sub-Channel 27 0x0D80

FIFO Sub-Channel 28 0x0E00

FIFO Sub-Channel 29 0x0E80

FIFO Sub-Channel 30 0x0F00

FIFO Sub-Channel 31 0x0F80

Table 10: Address Usage for Channel FIFO

Address Tag Value Tag Bit Meaning

0b 0000 0000 0000 001x xxxx xxxx xx00 0000+ C_BASEADDR

Tag(0 to 3) = 0x0Normal Data4 bytes to TX, not EOP


Tag(0 to 3) = 0x1 Undefined






Tag(0 to 3) = 0x4End of packet (EOP)4 bytes valid


Tag(0 to 3) = 0x5End of packet (EOP) 1 byte valid


Tag(0 to 3) = 0x6End of packet (EOP) 2 bytes valid


Tag(0 to 3) = 0x7End of packet (EOP) 3 bytes valid

Table 9: HDLC FIFO Sub Channel Offset Values (Contd)




18


FIFO Sub-channel(0 to 7) Address Bits(18 to 25)

FIFO sub-channel(0 to 7) 0 is the MSB (address bit 18) and 7 is the LSB (address bit 25). The MSB is used to select between either a Tx channel (MSB = 0) or a Rx channel (MSB = 1). The remainder of the bits in this range are used to select a sub-channel.

FIFO Phy channel(0 to 3) Address Bits(14 to 17)

Each physical HDLC interface contains an independent Tx Channel FIFO and independent Rx Channel FIFO.

Example Memory Map

This example is based upon a system that contains eight physical channels 32 sub-channels and a receive and transmit memory depth of 2048 for each physical channel. Only two physical and two sub-channels are shown in Table 11.






Tag(0 to 3) = 0xA Undefined


Tag(0 to 3) = 0xB Undefined


Tag(0 to 3) = 0xC Undefined


Tag(0 to 3) = 0xD Undefined


Tag(0 to 3) = 0xE Undefined


Tag(0 to 3) = 0xF Undefined

Table 11: Example Memory Map Consisting of 8 Physical Channels, 32 sub-channels 2048 bytes Rx and Tx Memory depth for all physical channels

Category Relative Absolute Description

HDLC Device

+ 0x0000 + 0x0000 IPIF Registers

+ 0x1000 + 0x1000 Status FIFO

+ 0x1100 + 0x1100 Device Control Register

+ 0x1104 + 0x1104 Tx Event FIFO

+ 0x1108 + 0x1108 Rx Event FIFO

Table 10: Address Usage for Channel FIFO (Contd)

Address Tag Value Tag Bit Meaning




DS438 DecProduct Sp


Physical Channel 0

+ 0x1110 + 0x1110 Physical Channel 0 Control Register

+ 0x1114 + 0x1114 Aborted Frame Counter

+ 0x1118 + 0x1118 CRC Error Counter

Physical Channel 1

+ 0x1120 + 0x1120 Physical Channel 1 Control Register

+ 0x1124 + 0x1124 Aborted Frame Counter

+ 0x1128 + 0x1128 CRC Error Counter

Physical Channel 0

Sub-channel 0+ 0x18000 (Physical Offset)+ 0x00000 (Sub Channel Offset)

+ 0x18000 Tx Control (TXCR(0,0))

Physical Channel 0 Sub-channel 1

+ 0x18000 (Physical Offset)+ 0x00020 (Sub Channel Offset)


Physical Channel 0Sub-channel 0

+ 0x18000 (Physical Offset)+ 0x00000 (Sub Channel Offset) + 0x00800 (Constant Offset)

+ 0x18800 Rx Control (RXCA(0,0))


+ 0x18000 (Physical Offset)+ 0x00020 (Sub Channel Offset)+ 0x00800 (Constant Offset)

+ 0x18820 Rx Control RXCA(0,1))

Physical Channel 0

Sub-channel 0

+ 0x20000 (FIFO Offset)+ 0x00000 (FIFO Sub Offset)+ 0x00000 (Tag Offset)

+ 0x20000

Write - TXDF(0,0) normal Tx data as defined in Table 10Read - TXDFS(0,0) Tx Data FIFO Status

Physical Channel 0

Sub-channel 0

+ 0x20000 (Physical Offset)+ 0x00000 (FIFO Sub Offset)+ 0x00004 - 0x0003C (Tag Offset)

+ 0x20004 through

+ 0x2003C

Write - TXDF(0,0) as defined in Table 10Read - undefined


+ 0x20000 (Physical Offset)+ 0x00000 (FIFO Sub Offset)+ 0x02000 (Constant Offset)

+ 0x22000Write - UndefinedRead - RXDFS(0,0) Rx Data FIFO Status



+ 0x22004Write - UndefinedRead - RXDF(0,0) Rx Data FIFO


+ 0x20000 (Physical Offset)+ 0x00080 (FIFO Sub Offset)+ 0x00000 (Tag Offset)

+ 0x20080




+ 0x20084 through

+ 0x200BC





Table 11: Example Memory Map Consisting of 8 Physical Channels, 32 sub-channels 2048 bytes Rx and Tx Memory depth for all physical channels (Contd)





20





Physical Channel 1

Sub-channel 0+ 0x19000 (Physical Offset)+ 0x00000 (Sub Channel Offset)



+ 0x19000 (Physical Offset)+ 0x00020 (Sub Channel Offset)

+ 0x19020 Tx Control TXCR(1,1))







Physical Channel 1

Sub-channel 0


+ 0x24000

Write - TXDF(1,0) normal Tx data as defined in Table 10Read - TXDFS(1,0)Tx Data FIFO Status



+ 0x24004

through

+ 0x2403C


Physical Channel 1

Sub-channel 0



Physical Channel 1

Sub-channel 0





+ 0x24080




+ 0x24084

through

+ 0x240B4








Table 11: Example Memory Map Consisting of 8 Physical Channels, 32 sub-channels 2048 bytes Rx and Tx Memory depth for all physical channels (Contd)





DS438 DecProduct Sp


HDLC Device Control Register (MSCR), C_BASE_ADDR + 0x1100

There is one HDLC Device Control Register for the entire HDLC device, regardless of the number of physical channels or sub-channels specified. The bit definitions are shown in Table 12.

Figure 3: HDLC Device Control Register Bit Mapping

Figure Top x-ref 3

addr_bus_usage_channel_fifos.eps

0 3 4 3029 31

MSB LSB Unused

Number of Physical

Channels - 1

MSEN

TXSEN

Table 12: HDLC Device Control Register Bit Definitions

Bit(s) Name Access Reset Value Description

0 - 3 NPC ReadC_NUM_

CHANNELS - 1

Number of Physical Channels - 1.This is the generic C_NUM_CHANNELS - 1 that is a read only. Writing to these bits is ignored and has no effect.

4-29 Unused Undefined Reserved

30 TXSEN Read/Write 0

Transmit Status Write Enable.Setting this bit to a 0 prevents all transmit status from being written into the Status FIFO. All receive status will still be written to the Status FIFO.Setting this bit to a 1 is required to use DMA and allows transmit status and transmit data length to be written into the Status FIFO.

31 MSEN Read/Write 0

Master Enable.Setting this bit to a 0 prevents the HDLC from receiving or transmitting any data. All registers should be initialized prior to setting this bit to a 1

Status FIFO (SF) C_BASE_ADDR + 0x1000

There is one Status FIFO for the entire HDLC device, regardless of the number of physical channels or sub-channels specified. This FIFO is 16 locations deep and is read only. The The Status FIFO bit mapping is shown in Figure 4, while the bit definitions are listed in Table 13.

Figure 4: Status FIFO Bit Mapping

Figure Top x-ref 4

0 3 4 98 10 23 24 25 31

Length

EOPTx - 0Rx - 1

Sub-Channel Status

status_fifo_bit_mapping.epsPhysical Channel




22


Table 13: HDLC Status FIFO Bit Definitions


0-3Physical Channel

Read UndefinedPhysical Channel Number.This field contains the binary encoding of the Physical Channel number. Data Bit 0 is the MSB

4 - 8Sub-

channelRead Undefined

Sub-Channel Number.This field contains the binary encoding of the Sub-Channel number. Data Bit 4 is the MSB.

9 RxTx Read UndefinedRxTx.Tx = 0Rx = 1

10 - 23 Length Read UndefinedThis is the number of bytes of data that has been written to the Rx Channel FIFO, or the number of bytes of data that has been read from Tx Channel FIFO.

24 EOP Read UndefinedEnd of Packet. This bit will be set high to indicate that the final byte has been received. This bit is undefined for transmit status.

25 - 27 Status(1) Read Undefined Reserved Status Bits

28 RXFA(1) Read UndefinedRX Frame Aborted. This bit will be set to a 1 when the last frame was aborted. This bit is cleared upon receiving the end flag of a complete frame.

29 RXFCS(1) Read UndefinedRX FCS Error. The last received frame contained an error. This bit will be set to a 1 once the end flag has been received if the frame contained an error.

30 RXAE(1) Read UndefinedRX Alignment Error. This bit is set to a 1 whenever the receiver did not receive an integer number of bytes.

31 RXBA(1) Read UndefinedBroadcast Address Received. This bit is set high when a transmitter has issued a broadcast address and the broadcast address match bit is set high, RXCA(30) = 1.

Notes: 1. The HDLC only returns a receive status, these bits are undefined and unused for a transmit status

HDLC Events

The HDLC events are converted into interrupts by the IPIF interrupt register set. The HDLC has multiple Transmit (Tx) and Receive (Rx) events. These Tx and Rx events are stored in separate event FIFOs. The event FIFOs are 16 locations deep and are read only. The following six events are managed by the IP Interrupt Source Controller Function which is contained in the IPIF module. This interface provides many of the features commonly provided for interrupt handling. The IPIER and IPISR contain the bit mapping as shown in Figure 5. Please refer to the Processor IP Reference Guide under Part 1: Embedded Processor IP, under IPIF, under OPB IPIF Architecture, under OPB IPIF Interrupt for a complete description of the IPIF interrupt processing including the GIE, IPISR and IPIER. The number in the parenthesis is the IPIF interrupt bit number. The bit definitions are described below.




DS438 DecProduct Sp


Figure 5: HDLC Event Mapping

Figure Top x-ref 5

26250 27 28 29 30 31

Event(4)

Event(2)

Event(0)

Event(5)

Event(3)

Event(1)

Unused

hdlc_event_mapping.eps

Event(0) -- Tx Event FIFO not empty

This event indicates that one or more of the events listed in Table 14 has occurred. The Tx event FIFO must be read to determine the physical channel and sub-channel number and the event condition. This event will remain active until the Tx event FIFO is empty.

Event(1) -- Tx Event FIFO Full

This event indicates that one or more of the events listed in Table 14 occurred, but that the Tx event FIFO was full and unable to store the latest event. This indicates that information has been lost and the recommended approach to recover from this condition is that the HDLC device transmit channels, both the physical and sub-channels, should be reset to initial conditions.

Event(2) -- Rx Event FIFO not empty

This event indicates that one or more of the events listed in Table 15 has occurred. The Rx event FIFO must be read to determine the physical channel and sub-channel number and the event condition. This event will remain active until the Rx event FIFO is empty.

Event(3) -- Rx Event FIFO Full

This event indicates that one or more of the events listed in Table 15 occurred, but that the Rx event FIFO was full and unable to store the latest event. This indicates that information has been lost and the recommended approach to recover from this condition is that the HDLC device receive channels, both the physical and sub-channels, should be reset to initial conditions.

Event(4) -- HDLC Status FIFO not empty

This event indicates that data exists in the HDLC Status FIFO.

Event (5) -- HDLC Status FIFO Full

Indicates that the HDLC Status FIFO became full during the reception or transmission of a packet and data was lost. This indicates that information has been lost and the recommended approach to recover from this condition is that the HDLC, both physical and sub-channels, should be reset to initial conditions.

HDLC Tx Event FIFO (TXEF) C_BASE_ADDR + 0x1104

There is one HDLC Tx Event FIFO for the device. This FIFO is 16 location deep and is read only. The HDLC Tx Event FIFO bit mapping is shown inFigure 6, while the bit definitions are shown in Table 14.




24


Figure 6: HDLC Tx Event FIFO Bit Mapping

Figure Top x-ref 6

2928 30 31

Tx_Event(1)

Tx_Event(2)Tx_Event(0)

UnusedReserved

PhysicalChannel Sub-Channel

hdlc_tx_event_fifo_bit_mapping.eps

30 4 76 11 12

Table 14: HDLC Tx Event FIFO

Bit(s) Name AccessReset Value

Description

0 - 3Physical Channel

Read 0Physical Channel NumberBit 0 is the MSB of the Physical Channel Number.

4 - 6 Reserved Read 0Reserved.Reserved for future sub channel growth.

7 - 11 Sub-Channel Read 0Sub Channel NumberBit 7 is the MSB of the Sub-Channel Number.

12 - 28

Unused Undefined Reserved

29 Tx_Event (2) Read 0

Tx_Event (2) -- Tx Channel FIFO Half EmptyIndicates that the Tx channel FIFO is half empty. This event is only caused by the Tx channel FIFO transitioning from less than half empty to more than half empty.

30 Tx_Even t(1) Read 0Tx_Event (1) -- Tx dual port underrunIndicates that a Tx dual port underrun occurred. This event occurs if the Tx data rate is to high relative to the OPB_CLK.

31 Tx_Event (0) Read 0

Tx_Event (0) -- Transmit CompleteEvent(0) is the transmit complete. This event will occur as the last byte of data is being transmitted, prior to the transmission of the CRC or the ending flag. This event is a pulse and there is no action required by software to clear this event condition.

HDLC Rx Event FIFO (RXEF) C_BASE_ADDR + 0x1108

There is one HDLC Rx Event FIFO for the device. This FIFO is 16 location deep and is read only. The HDLC Rx Event FIFO bit mapping is shown in Figure 7, while the bit definitions are shown in Table 15.




DS438 DecProduct Sp


Figure 7: HDLC Rx Event FIFO Bit Mapping

Figure Top x-ref 7

2928 30 31

Rx_Event(1)

Rx_Event(2)Rx_Event(0)

UnusedReserved

PhysicalChannel Sub-Channel

hdlc_rx_event_fifo_bit_mapping.eps

30 4 76 11 12

Table 15: HDLC Rx Event FIFO


Description

0 - 3Physical Channel

Read 0Physical Channel NumberBit 0 is the MSB of the Physical Channel Number.

4 - 6 Reserved Read 0Reserved.Reserved for future sub channel growth.

7 - 11Sub-

ChannelRead 0

Sub Channel NumberBit 7 is the MSB of the Sub-Channel Number.

12 - 28 Unused Undefined Reserved

29 Rx_Event (2) Read 0Rx_Event (2) -- Rx dual port overrunIndicates that an Rx dual port overrun occurred. This event occurs if the Rx data rate is to high relative to the OPB_CLK.

30 Rx_Event (1) Read 0

Rx_Event (1) -- CRC counter or Aborted frames counter rollover eventIndicates that either the CRC counter incremented from 65535 to 0 or the aborted frames counter incremented from 65535 to 0.

31 Rx_Event (0) Read 0

Rx_Event (0) -- Receive Data FIFO Overrun eventIndicates that the receive data FIFO became full during the reception of a packet and data was lost. Receive packets stored in the FIFO should be processed to free up more locations. This event occurs every time an attempt to write data to the FIFO and the FIFO is full.

HDLC Physical Control Register (PCCR) C_BASE_ADDR + 0x1110, 0x1120, 0x1130, ...

There will be one HDLC Physical Control Register for each physical channel. The HDLC Physical Control Register bit mapping is shown in Figure 8, while the bit definitions are shown in Table 16.




26


Figure 8: HDLC Physical Control Register Bit Mapping

Figure Top x-ref 8

2928 30 31

LoopRXEN

TXEN

Number of Sub-Channels - 1

MSB LSB Unused

hdlc_phy_control_register_bit_mapping.eps

0 7 8

Table 16: HDLC Physical Control Register Bit Definitions


0 - 7 NSC ReadC_NUM_SUB_CHANNELS - 1

Number of Sub-Channels - 1.This is the generic C_NUM_SUB_CHANNELS - 1 that is a read only. Writing to these bits is ignored and has no effect.


29 RXEN Read/Write 0

HDLC Receiver Enable. This bit must be set before any of the RXCA bits have an effect.1 enables the HDLC RX controller.0 disables the HDLC RX controller.

30 TXEN Read/Write 0

HDLC Transmitter Enable. This bit must be set before any of the TXCR bits have an effect. 1 enables the HDLC TX controller. 0 disables the HDLC TX controller.

31 LOOP Read/Write 0

Loop Back Test. Note that when toggling this bit, it is best if the receiver is disabled (RXEN = 0) to prevent any spurious events from occurring. Loop Back Test is not supported with DMA.1 - Loop Back Test is enabled0 - Loop Back Test is disabled

Number of Aborted Frames (ABRT) C_BASE_ADDR + 0x1114, 0x1124, 0x1134, ...

This field contains the number of aborted frames received per physical channel. The value will count to 65535, then rollover to 0, and continue counting. A write of any value will reset this value. The bit mapping for this field is shown in Figure 9, while the Aborted Frame Counter bit definitions are listed inTable 17.

Figure 9: HDLC Number of Aborted Frames Bit Mapping

Figure Top x-ref 9

31

AFC_EN

Unused Rx Aborted Frame Count

hdlc_number_aborted_frames_bit_mapping.eps

15140 16




DS438 DecProduct Sp


Table 17: Aborted Frame Counter



15 AFC_EN Read/Write 0

Setting this bit to a 0 will disable event (9), counter rollover, from occurring.Setting this bit to a 1 will allow event (9), counter rollover, to be passed to the Rx Event FIFO and then to the IPIF for interrupt processing.

16-31Rx Aborted

Frame CountRead/Write 0x0000 This register is cleared to 0x00 with every write.

Number of CRC Errors (CRCE) C_BASE_ADDR + 0x1118, 0x1128, 0x1138, ...

This field contains the number of CRC errors received per physical channel. The value will count to 65535, then rollover to 0, and continue counting. A write of any value will reset this value. The bit mapping for this field is shown in Figure 10, while the bit description is listed in Table 18.

Figure 10: HDLC Number of CRC Errors Bit Mapping

Figure Top x-ref 10

31

CCT_EN

Unused Rx CRC Error Count

hdlc_number_crc_errors_bit_mapping.eps

15140 16

Table 18: FCS Error Counter


Description


15 CCT_EN Read/Write 0

Setting this bit to a 0 will disable event (9), counter rollover, from occurring.Setting this bit to a 1 will allow event (9), counter rollover, to be passed to the IPIF for interrupt processing.

16-31Rx CRC

Error Count

Read/Write 0x0000 This register is cleared to 0x00 with every write.

HDLC RX Sub-channel Control and Address (RXCA)

There is one HDLC RX Sub-channel Control and Address register for each sub-channel. The HDLC RX Control and Address Bit Mapping register is shown in Figure 11, while the bit mapping for this register is listed in Table 19.




28


Figure 11: HDLC Rx Sub-channel Control and Address Bit MappingFigure Top x-ref 11

hdlc_rx_subchan_control_addr_bit_mapping.eps

0 7 8 1615 17 27 282625 29 30 31

High Byte of Slave Address Rx_Event(0)EN Unused ADSIZE RXSEN

Low Byte of Slave Address CRC ADREC BAMEN

RMADDR

Table 19: HDLC RX Control and Address Bit Definitions


Description

0-7High Byte of

Slave Address

Read/Read Modify Write

UndefinedAddress used by the OPB HDLC RX Interface for 16 bit addresses

8-15Low Byte of

Slave Address

Read/Read Modify Write

UndefinedAddress used by the OPB HDLC RX Interface for 8 or 16 bit addresses

16Rx_Event

(0)_EnRead/Read Modify Write

Undefined

Rx_Event(0)_En. Receive Data FIFO Overrun enable. Setting this bit to a 0 will disable the Receive Data FIFO Overrun RX_Event(1). Setting this bit to a 1 will allow the Receive Data FIFO Overrun RX_Event(1) to be passed to the IPIF for further interrupt processing.

17 - 25 ReservedRead/Read Modify Write

Undefined Reserved

26 CRCRead/Read Modify Write

UndefinedCRC select. 1 - CRC-32 is used for the FCS field0 - CRC-CCITT is used for the FCS fields.

27 ADSIZERead/Read Modify Write

UndefinedAddress Size. 1 - 16 bits of address are used for address recognition.0 - 8 bit of address are used for address recognition.

28 ADRECRead/Read Modify Write

Undefined

Address Recognition. 1 Address and data is written to the receive memory buffer when the address received matches the address stored in the address register(s).0 All addresses and data is written to the receive memory buffer




DS438 DecProduct Sp


HDLC TX Sub-channel Control Register (TXCR)

The HDLC TX Sub-channel Control Register is shown in Figure 12, while the bit definitions for the register are listed Table 20.

Figure 12: HDLC Tx Sub-channel Control Register Bit Mapping

Figure Top x-ref 12

hdlc_tx_subchan_control_register_bit_mapping.eps

0 171615 18 2827 29 30 31

Unused Tx_Event(2)EN Unused DISCRC TXFA

Tx_Event(0)EN TXCRC TXSEN

29 RMADRRead/Read Modify Write

Undefined

Address Field Removed. Note that when the Address Recognition is set to 0 the address field is written to the receive buffer regardless of this bit setting.1 The address field is not written to the receive memory buffer0 The address field is written to the receive memory buffer

30 BAMENRead/Read Modify Write

Undefined

Broadcast address match. This bit will determine if the receiver responds to a broadcast address.1 Receiver does respond to an 8 bit broadcast address (0XFF).0 Receiver does not respond to a broadcast address.

31 RXSENRead/Read Modify Write

Undefined

HDLC Receiver Sub-channel Enable. This bit must be set before any other CR bits have any effect.1 enables the HDLC RX controller.0 resets and disables the HDLC RX controller.

Table 20: HDLC TX Control Register Bit Definitions


0-15 Reserved Undefined Reserved.

16Transmit Complete

Event(0) EnableRead/Write

Undefined

Transmit Event(0) Enable. Setting this bit to a 0 will disable the Transmit Complete Event(0). Setting this bit to a 1 will allow the Transmit Complete Event(0) to be passed to the IPIF for further interrupt processing.

17Transmit Complete

Event(2) EnableRead/Write Undefined

Transmit Event(2) Enable. Setting this bit to a 0 will disable the Transmit Complete Event(2). Setting this bit to a 1 will allow the Transmit Complete Event(2) to be passed to the IPIF for further interrupt processing.

18 - 27 Reserved Undefined Reserved.

Table 19: HDLC RX Control and Address Bit Definitions (Contd)


Description




30


Receive (read) Data Channel FIFO Status (RXDFS)

There is one Receive Data Channel FIFO Status for each sub-channel. The register bit mapping is shown in , while the bit definitions are described in Table 21.

Figure 13: HDLC Receive Data Channel FIFO Status Bit Mapping

Figure Top x-ref 13

hdlc_rec_data_chan_fifo_stat_bit_mapping.eps

0 2 31 31

Almost Empty Occupancy

Empty HalfEmpty

28 DISCRCRead/Write

Undefined

Disable CRC Generation.1 = A CRC value of all zeros will generated and appended on to the transmitted data.0 = CRC will be generated and appended on to the transmitted data.

29 TXCRC Read/Write UndefinedTX CRC size. 1 = CRC-32 is used for the FCS field0 = CRC-CCITT is used for the FCS field

30 TXFA Read/Write1 Undefined

TX Frame Abort. Setting this bit to a 1 will cause the transmitter to initiate a frame abort sequence. Abort flags will be sent as long as this bit is set to a 1.

31 TXSEN Read/Write Undefined

HDLC Transmitter Sub-channel Enable. This bit must be set before any other TXCR bits have any effect. 1 enables the HDLC transmitter to read data, if present, from the transmit channel FIFO. 0 prevents the HDLC transmitter from reading data out of the transmit channel FIFO. This does not prevent any data currently in the 32 shift register or the CRC or idle flags from being transmitted.

Notes: 1. The abort flag must occur between a start flag and an ending flag for the receiver to detect and report the abort

condition. The transmitter will transmit all data remaining in the packet before generating the abort flag.

Table 21: Receive Data Channel FIFO Status


0 Empty ReadRXDFS Empty -- Please refer to the Xilinx Channel FIFO for the complete specification of the receive channel FIFO status

1Almost Empty

ReadRXDFS Almost Empty -- Please refer to the Xilinx Channel FIFO for the complete specification of the receive channel FIFO status

Table 20: HDLC TX Control Register Bit Definitions (Contd)





DS438 DecProduct Sp


Receive (read) Data Channel FIFO (RXDF)

This field contains data received from the HDLC. See Figure 14 and Table 22.

Figure 14: HDLC Receive Data

Figure Top x-ref 14

hdlc_receive_data.eps

0 31

Rx Data

Table 22: Receive Memory Buffer


0-31 RXDF ReadReceived Data is buffered in this FIFO prior to either a DMA or software transfer.(1,2)

Notes: 1. For example if a Virtex-II is chosen and the receive memory depth is set for 65536 bytes (32 BRAMs will be

used) and 24 sub-channels is selected, then each sub channel will have 2048 bytes of buffering, ((65536/32) - 4). 65536 is the receive memory depth, 32 is the next power of two equal to or greater than the number of sub-channels, and 4 bytes are used for sub channel FIFO status.

2. Please refer to the Xilinx Channel FIFO for the complete specification of the receive (read) channel FIFO data.

Transmit (write) Data Channel FIFO Status (TXDFS)

There is one Transmit Data Channel FIFO Status for each sub-channel. See Figure 15and Table 23.

Figure 15: HDLC Transmit Data Channel FIFO Status Bit Mapping

Figure Top x-ref 15

hdlc_trans_data_chan_fifo_stat_bit_mapping.eps

0 2 3 41 31

AlmostFull Empty Vacancy

HalfFull

Full

2Half

EmptyRead

RXDFS Half Empty -- Please refer to the Xilinx Channel FIFO for the complete specification of the receive channel FIFO status

3-31 RXDFS ReadRXDFS Occupancy -- Please refer to the Xilinx Channel FIFO for the complete specification of the receive channel FIFO status

Table 21: Receive Data Channel FIFO Status




32


Table 23: Transmit Data Channel FIFO Status


0 Full ReadTXDFS Full -- Please refer to the Xilinx Channel FIFO for the complete specification of the transmit (write) channel FIFO status

1Almost

FullRead

TXDFS Almost Full -- Please refer to the Xilinx Channel FIFO for the complete specification of the transmit (write) channel FIFO status

2 Half Full ReadTXDFS Half Full -- Please refer to the Xilinx Channel FIFO for the complete specification of the transmit (write) channel FIFO status

3 Empty ReadTXDFS Empty -- Please refer to the Xilinx Channel FIFO for the complete specification of the transmit (write) channel FIFO status

4-31 Vacancy ReadTXDFS Vacancy -- Please refer to the Xilinx Channel FIFO for the complete specification of the transmit (write) channel FIFO status

Transmit (write) Channel FIFO (TXDF)

This field contains the data to be transmitted on the HDLC. See Figure 16 and Table 24.

Figure 16: HDLC Transmit Data

Figure Top x-ref 16

hdlc_transmit_data.eps

0 31

Tx Data

Table 24: Transmit Memory Buffer


0-31 TXDF Write UndefinedTransmit Data is buffered in this FIFO prior to the HDLC

transmitting this data.(1,2)

Notes: 1. For example if a Virtex-II is chosen and the receive memory depth is set for 65536 bytes (32 BRAMs will be

used) and 5 sub-channels is selected then each sub channel will have 8188 bytes of buffering, ((65536/8) - 4). 65536 is the transmit memory depth, 8 is the next power of two equal to or greater than the number of sub-channels, 4 bytes are used for each sub-channel FIFO status

2. Please refer to the Xilinx Channel FIFO for the complete specification of the transmit (write) channel FIFO data.




DS438 DecProduct Sp


HDLC Block DiagramFigure 17 shows the top-level block diagram for the single channel HDLC.

Figure 17: HDLC Module Block Diagram

Figure Top x-ref 17

ByteCount

CRCCheck

ZeroDelete

RagMatch

AddrDetect

CRCE

ABRT

PhysicalChannel

PCCR

ByteCount

CRCGen

ZeroInsert

RagGen

Rx LengthFIFO

Rx StatusFIFO

Rx FrameControl

Rx Controland Status

Tx LengthFIFO

Tx StatusFIFO

Tx FrameControl

Tx Controland Status

BRAM Contex Storagesub-channel registers

Rx Channel FIFO1 BRAM minimum

32 BRAM maximum


32 BRAM maximum

DualPortFIFO

rxd

OPB_CLK

DualPortFIFO

txd

OPB_CLK

LoopBackDualPortFIFO

txd

OPB_CLK

rxcl loop back

HDLC #1 1-32 TDM Sub Channels

RXDO

RXCLK0

TXCLK0

RXDEN0

TXDEN0

TXD0

RX_CHN_SEL0

TX_CHN_SEL0

RXD1

RXCLK1

TXCLK1

RXDEN1

TXDEN1

TXD1

RX_CHN_SEL1

TX_CHN_SEL1

RXD7

RXCLK7

TXCLK7

RXDEN7

TXDEN7

TXD7

RX_CHN_SEL7

TX_CHN_SEL7

ByteCount

CRCCheck

ZeroDelete

RagMatch

AddrDetect

OCRE

ABRT

PhysicalChannel

POOR

ByteCount

CRCGen

ZeroInsert

RagGen

Rx LengthFIFO

Rx StatusFIFO

Rx FrameControl


Tx LengthFIFO

Tx StatusFIFO

Tx FrameControl




32 BRAM maximum


32 BRAM maximum

DualPortFIFO

rxcl

OPB_CLK

DualPortFIFO

rxcl

OPB_CLK


rxcl

OPB_CLK

rxcl loop back


ByteCount

CRCCheck

ZeroDelete

RagMatch

AddrDetect

OCRE

ABRT

PhysicalChannel

POOR

ByteCount

CRCGen

ZeroInsert

RagGen

Rx LengthFIFO

Rx StatusFIFO

Rx FrameControl


Tx LengthFIFO

Tx StatusFIFO

Tx FrameControl




32 BRAM maximum


32 BRAM maximum

DualPortFIFO

rxcl

OPB_CLK

DualPortFIFO

rxcl

OPB_CLK


rxcl

OPB_CLK

rxcl loop back


DeviceRegisterInterface

StatusFIFO

Event 4 & 5

Tx EventFIFO

Event 0 &1

MSCR

Rx EventFIFO

Event 2 & 3

IPIFRegister Set

Containing a256 Channel

DMA Controller

IPIF

hdlc_multichan_if_block_diagram.eps

Frame Check Sequence (FCS)

This block provides a CRC generation. The block is preset to force the registers to a 1 (and hence comply to CCITT specifications). The CRC Calculator generates a CRC code from the following polynomials.

CRC-CCITT shown in Figure 18 uses the following polynomial.

G(x) = x16 + x12 + x5 + 1.




34


Figure 18: CRC - CCITT Code Generation

Figure Top x-ref 18

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

DataOutData In

Clock In

crc_code_generation.eps

CRC-32, shown in Figure 19 uses the following polynomial.

G(x)=x32+x26+x23+x22+x16+x12+x11+x10+x8+x7+x5+x4+x2+x+1

Figure 19: CRC-32 Code Generation

Figure Top x-ref 19

0 2 31

1716 18 19 20 2928 30 3122

12 13 14 154 5 6 7 8 9 1110

Data Out

Data In

Clock In

crc32_code_generation.eps

2423 25 272621

Time Division Multiplexing (TDM)

The HDLC can support 1 to 32 TDM channels on a single physical channel.

If a physical channel is configured to have one sub channel then this physical channel does not implement any TDM functions. The transmit or receive data rate must be at least 10% slower than the OPB_CLK, a 100MHz OPB_CLK requires the Rx/Tx data rate to be less than or equal to 90MHz. The transmit data rate is determined by TxClk and Txden. The receive data rate is determine by RxClk and Rxden. There is a small asynchronous dual port FIFO that will buffer the Tx and Rx data. An overrun or under run of these FIFO is an error condition and is reported through the Tx or Rx Event FIFOs. This error condition indicates that the data rate is higher than the HDLC can handle.

If a physical channel has two or more sub channels configured than the TDM function is implemented. The transmit or receive data rates must be less the 1/3 the OPB_CLK, a 100MHz OPB_CLK requires the Tx/Rx data rate to be less than or equal to 33.3MHz. The TDM function uses internal BRAM to context switch the state of each sub channel, the current sub channel state is stored and the next sub channel state is retrieved. Figure 21 shows the timing for three different configurations of a physical channel, no TDM, TDM with two sub channels and TDM with 32 sub channels.

The transmit TDM will always start at sub channel zero and transmit 8 bits and then increment to sub channel 1 and transmit 8 bits. The sub channel will increment through the number of sub channels configured for this physical channel and then return to sub-channel zero. The Tx_Chnl_Sel indicates which sub channel the data bit is being transmitted to. The Txden and/or the TxClk can be used to control the data output from the Tx channel.

The receive TDM channel is controlled by the Rx_Chnl_Sel input. Every time a change is detected on the Rx_Chnl_Sel a context switch occurs and processing on the new sub channel continues until a new sub channel is detected. It is possible to change sub channels with every RxClk, however a context switch requires up to 14 OPB_CLKs to perform the context switch so the Rx data rate must be less than or equal to 1/14 the OPB_CLK.




DS438 DecProduct Sp


Figure 20: Timing Information

Figure Top x-ref 20

Tx Channel 0 Tx Channel 1 Tx Channel 0 Tx Channel 1 Tx Channel 0 Tx Channel 1 Tx Channel 00 7 0 7 0 7 0 7 0 7 0 7 0 7 0

Tx Clock

Tx Clock

Tx Data Tx Data

Tx Channel 0 Tx Channel 1 Tx Channel 2 Tx Channel 3 Tx Channel 30 Tx Channel 31 Tx Channel 00 7 0 6 0 7 0 7 0 7 0 7 0 7

Tx Clock

1 2 3 4 5 6 1 2 3 4 5 6

Txden

Txden

1 2 3 4 5 7 0 71 2 3 4 5 6

Txden

Tx Data Tx Data

32 Sub Channels configured

2 Sub Channels configured

Single Sub Channel configured

Figure 21: I/O Timing

Figure Top x-ref 21

TxClk

TxDen

TxD

Tx_Chnl_Sel

RxClk

RxDen

Rx_Chnl_Sel

RxD

Eighth bit of Chnl 0 First bit of Chnl 1 Second Bit of Chnl 1

Channel 0 Channel 1

Tsu

Th

Tsu

Th

Tsu

Th

Tsu

Th

Clk_to_Q Clk_to_Q Clk_to_Q

Tsu

Tsu

Th

Th

Clk_to_Q

Tsu

Tsu

Th

Th

Clk_to_Q

Tsu

Th

Tsu

Tsu

Th

Th

Clk_to_Q

Design Implementation

Design Tools

Xilinxs XST is the synthesis tool used for synthesizing the HDLC.

Target Technology

The intended target technology is a Virtex-II Pro FPGA.




36


Device Utilization and Performance Benchmarks

Because the HDLC is a module that will be used with other design pieces in the FPGA, the utilization and timing numbers reported in this section are just estimates. As the HDLC is combined with other pieces of the FPGA design, the utilization of FPGA resources and timing of the HDLC design will vary from the results reported here.

In order to analyze the HDLC timing within the FPGA, a design was created that instantiated the HDLC with the following parameters set.

The HDLC benchmarks are shown in Table 25 for a Virtex-II XC2V6000-6 FPGA, using Design Manager release version 6.2.01i application version G.29.

Table 25: OPB HDLC Interface FPGA Performance and Resource Utilization Benchmarks (Virtex-II XC2V6000-6)

Parameter Values Device Resources fMAX

C_D

MA

_PR

ES

EN

T

C_N

UM

_CH

AN

NE

LS

C_N

UM

_SU

B_C

HA

NN

ELS

_0

C_N

UM

_SU

B_C

HA

NN

ELS

_1

C_N

UM

_SU

B_C

HA

NN

ELS

_2

C_N

UM

_SU

B_C

HA

NN

ELS

_3

C_N

UM

_SU

B_C

HA

NN

ELS

_4

C_N

UM

_SU

B_C

HA

NN

ELS

_5

C_N

UM

_SU

B_C

HA

NN

ELS

_6

C_N

UM

_SU

B_C

HA

NN

ELS

_7

C_T

X_M

EM

_DE

PT

H(4

)

C_R

X_M

EM

_DE

PT

H(4

)

C_N

UM

_SU

B_C

HA

NN

EL_

BIT

SS

_0

C_N

UM

_SU

B_C

HA

NN

EL_

BIT

SS

_1

C_N

UM

_SU

B_C

HA

NN

EL_

BIT

SS

_2

C_N

UM

_SU

B_C

HA

NN

EL_

BIT

SS

_3

C_N

UM

_SU

B_C

HA

NN

EL_

BIT

SS

_4

C_N

UM

_SU

B_C

HA

NN

EL_

BIT

SS

_5

C_N

UM

_SU

B_C

HA

NN

EL_

BIT

SS

_6

C_N

UM

_SU

B_C

HA

NN

EL_

BIT

SS

_7

Slic

es

Slic

e F

lip-F

lops

4-in

put L

UT

s

BR

AM

s

GC

LKs

MH

z

IPIF

Rem

oved

NA 1 1 0 0 0 0 0 0 0

2048

2048 1 0 0 0 0 0 0 0 743

604

1078 2 1(3)

151

NA 1 1 1 0 0 0 0 0 0 0

2048

2048 1 0 0 0 0 0 0 0 860

794

1203 2 1(3)

151

NA 2 1 1 0 0 0 0 0 0 0

2048

2048 1 0 0 0 0 0 0 0

1614

1246

2513 3 1(3)

100

NA 1 1 2 0 0 0 0 0 0 0

2048

2048 1 0 0 0 0 0 0 0

1172

864

1942 4 1(3)

144

NA 2 1 2 0 0 0 0 0 0 0

2048

2048 1 0 0 0 0 0 0 0

1939

1319

3256 5 1(3)

100

NA 1 1 2 0 0 0 0 0 0 0

4096

4096 1 0 0 0 0 0 0 0

1176

874

1955 6 1(3)

117

NA 1 1 4 0 0 0 0 0 0 0

2048

2048 2 0 0 0 0 0 0 0

1151

852

1903 4 1(3)

119

NA 1 1 8 0 0 0 0 0 0 0

2048

2048 3 0 0 0 0 0 0 0

1143

845

1893 4 1(3)

119

NA 1 1 16 0 0 0 0 0 0 0 2048

2048 4 0 0 0 0 0 0 0

1143

838

1874 4 1(3)

115

NA 1 1 24 0 0 0 0 0 0 0 2048

2048 5 0 0 0 0 0 0 0

1142

834

1879 4 1(3)

116

NA 1 1 24 0 0 0 0 0 0 0

6553

6

6553

6

5 0 0 0 0 0 0 0

1267

921

2062 74 1(3)

99

NA 1 1 32 0 0 0 0 0 0 0 2048

2048 5 0 0 0 0 0 0 0

1135

837

1862 4 1(3)

122




DS438 DecProduct Sp


Specification Exceptions

Exceptions to the HDLC specification

There are currently no known exceptions.

Reference DocumentsThe the International Telecommunication Union ITU-T Q.921 (09/97) reference document to gain a greater understanding of the OPB HDLC Interface design.

NA 2 1 32 0 0 0 0 0 0 0 2048

2048 5 0 0 0 0 0 0 0

1929

1302

3215 5 1(3)

100

NA 1 2 1 1 0 0 0 0 0 0

2048

2048 1 1 0 0 0 0 0 0

1541

1414

2091 4 1(3)

119

NA 1 2 1 2 0 0 0 0 0 0

4096

2048 1 1 0 0 0 0 0 0

1841

1504

2868 8 1(3)

119

NA 1 2 2 2 0 0 0 0 0 0

2048

2048 1 1 0 0 0 0 0 0

2156

1554

3638 8 1(3)

118

NA 1 2 32 32 0 0 0 0 0 0 2048

2048 5 5 0 0 0 0 0 0

2089

1496

3475 8 1(3)

108

NA 1 2 32 32 0 0 0 0 0 0

3276

8

3276

8

5 5 0 0 0 0 0 0

2279

1621

3817 76 1(3)

98

NA 1 4 1 1 1 1 0 0 0 0

2048

2048 1 1 1 1 0 0 0 0

2886

2648

3909 8 1(3)

125

NA 1 4 32 32 32 32 0 0 0 0 2048

2048 5 5 5 5 0 0 0 0

4047

2813

6703 16 1(3)

104

NA 1 8 1 1 1 1 1 1 1 1

2048

2048 1 1 1 1 1 1 1 1

5687

5116

7645 16 1(3)

104

NA 1 8 32 32 32 32 32 32 32 32 2048

2048 5 5 5 5 5 5 5 5

7887

5442

1318

4

32 1(3)

103

Notes: 1. These benchmark designs contain only the HDLC without any additional logic. Benchmark numbers approach the performance ceiling rather than

representing performance under typical user conditions. ISE version 6.1 was used for synthesis, map and PAR. The design was targeted into a Virtex-II Pro XC2vP20-fg676-6

2. The C_OPB_CLK_PERIOD_PS is set to 10000 for the above examples.3. It is preferable to use a global clock buffer for the Receive Clock and Transmit Clock. If global clock buffers are not used, care must be taken to ensure

the setup and hold times of the inputs are met.4. To reduce the complexity of this table all physical channels had the same value for C_TX_MEM_DEPTH, and for C_RX_MEM_DEPTH. This is not a

requirement for the design, but an attempt to make this table more readable.

Table 25: OPB HDLC Interface FPGA Performance and Resource Utilization Benchmarks (Virtex-II XC2V6000-6)




38


Revision History

Date Version Revision

05/01/03 2.0 Initial Xilinx release.

05/21/03 2.1 Update to current template; update for EDK minor SP2

07/15/03 2.2 Update for EDK Granite

3/29/04 2.3 Updates for DMA and Write Channel FIFO

5/1/04 2.4 Updated to new hardware version V2.01a

8/19/04 2.5 Updated for Gmm; updated trademarks and supported device family listing.

9/22/04 2.5.1In Table 16, added Loop Back Test is not supported with DMA to Description column for LOOP signal.

3/18/05 2.6Converted to new DS template; updated figures to Xilinx graphic standards; revised text for HDLC Design Parameters; added Figure 20; made other minor content edits; added Spartan-3E to supported device family listing.

12/1/05 2.7 Added Spartan-3E to supported device listing.



OPB Multi Channel HDLC Interface (v2.01a)IntroductionFeaturesEvaluation VersionHDLC ProtocolHDLC Design ParametersAllowable Parameter CombinationsHDLC I/O SignalsHDLC Port DependenciesHDLC Register DescriptionsIPIF Registers used by the HDLCHDLC RegistersExample Memory MapHDLC Device Control Register (MSCR), C_BASE_ADDR + 0x1100Status FIFO (SF) C_BASE_ADDR + 0x1000HDLC EventsHDLC Tx Event FIFO (TXEF) C_BASE_ADDR + 0x1104HDLC Rx Event FIFO (RXEF) C_BASE_ADDR + 0x1108HDLC Physical Control Register (PCCR) C_BASE_ADDR + 0x1110, 0x1120, 0x1130, ...Number of Aborted Frames (ABRT) C_BASE_ADDR + 0x1114, 0x1124, 0x1134, ...Number of CRC Errors (CRCE) C_BASE_ADDR + 0x1118, 0x1128, 0x1138, ...HDLC RX Sub-channel Control and Address (RXCA)HDLC TX Sub-channel Control Register (TXCR)Receive (read) Data Channel FIFO Status (RXDFS)Receive (read) Data Channel FIFO (RXDF)Transmit (write) Data Channel FIFO Status (TXDFS)Transmit (write) Channel FIFO (TXDF)HDLC Block DiagramFrame Check Sequence (FCS)Time Division Multiplexing (TDM)Design ImplementationDesign ToolsTarget TechnologyDevice Utilization and Performance BenchmarksSpecification ExceptionsExceptions to the HDLC specificationReference DocumentsRevision History

Xilinx DS438 OPB Multi Channel HDLC Interface … Multi Channel HDLC Interface (v2.01a) DS438...

Documents

Transcript of Xilinx DS438 OPB Multi Channel HDLC Interface … Multi Channel HDLC Interface (v2.01a) DS438...