AdvancedAdvanced MicrocontrollersMicrocontrollers

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LLectureecture 3:3:ElectricalElectrical parametersparameters ofof microcontrollersmicrocontrollers8051 8051 familyfamily

Plan

• Electrical parameters of microcontrollers

• 8051 core (8-bit)

– Main features

– 8051 based microcontrollers

Electrical parameters

Electrical parameters

• Important parameters:

– Maximum ratings

– Power supply:

• Voltage

• Current consumption

– Clocking

– Reset

– I/O ports parameters

Electrical parameters

Maximum ratings

Maximum ratings

• Microcontrollers have to be viewed as a

complicated device, sensitive to many factors

• Each device have their own Absolute

Maximum Ratings that must be viewed very

carefully

• The values found in that table MUST NOT be

exceeded

Maximum ratings

• Main parameters:

– Operating temperature

• Usually from -40C to 130C

• Differs from chip vendor to chip vendor

• Usually different temperature versions available

• Thermal resistance should be taken into consideration

in order to avoid problems with overheating

• Microcontrollers are usually NOT protected against

overheating!

Maximum ratings

• Main parameters:

– Maximum operating voltage:

• Maximum value of voltage that can be connected to

power supply input of the microcontroller

• For microcontrollers with multiple power supplies

inputs, the maximum operating voltage is defined for

each input separately

Maximum ratings

• Main parameters:

– Input / output voltage range:

• Maximum value of voltage that can be connected to

any pin of the microcontroller

• The value is usually limitted by the actual power supply

value and may stay within some limits (i.e. -0.5V to

VCC+0.5V)

• The input-output voltage range can be extended when

the CLAMP CURRENT parameter is used properly

Maximum ratings

• Main parameters:

– Clamp Current:

• The maximum current that the input can sink or the

output can source without any damage

• Usually in mA range

• If a series resistor is used then even very high or

negative voltages can be directly connected to the

microcontroller

• Usable in ESD protection

Electrical parameters

Power supply

Power supply

• Delivering power to microcontrollers is usually

a delicate task

• Most of microcontrollers have more than 1

power supply input

• Each power supply input have usually

different requirements

• The most problematic for proper power

supply are microcontrollers with analog part

Power supply

Dual supply

Single supply

System grounding

Ground shortened

only on power

supply

Grounds

shortened only

on uC

Grounds

shortened only

on uC

Current consumption

• The requirements on power consumption

reduction are nowdays very high

• The active supply current is in the range of

1mA/MIPS

• The active supply current depends on the

main clock frequency

• Microcontrollers offer many supply modes in

order to reduce power consumption

Current consumption

Electrical parameters

Clocking

Clocking

• External Crystal Oscillator:

– An external crystal oscillator is connected

between XTAL inputs

– Modifying clock frequency requires change of the

physical object (crystal)

– Clock stability can be high (1-10ppm)

Clocking

• Low Frequency Crystal Oscillator:

– Optimised for low frequency crystals – mainly the

32.768 kHz

– Similar stability like standard Crystal Oscillator

Clocking• External RC Oscillator:

– Very simple and cheap option

– Just two discreet components necessary

– Limited to a few MHz range

– Ease of frequency regulation

– Very low stability (100-1000 ppm)

Clocking• Internal RC Oscillator:

– Very simple and cheap option

– Limited to a few MHz range

– Ease of frequency regulation – only software

register change necessary

– Possibility of frequency calibration

– Very low stability (100-1000 ppm)

Clocking• External Clock:

– The most expensive option

– Just one (but complicated!) component necessary – the

clock generator

– Very wide frequency range available (even above 100MHz)

– No possiblity of frequency regulation

– High to Ultra high stability (0.000001 - 10 ppm)!!!

Clocking• Internal PLL:

– Requires external clock or external oscillator

– Wide frequency range available

– Ease of frequency regulation via software register

– Stability depends on the clock source and the

jitter of PLL. Usually not better than 1ppm

Electrical parameters

Reset

Reset

• During Reset:

– all I/O Registers are set to their initial values

– the program starts execution from the Reset

Vector

• The reset circuitry does not require any clock

source to be running (it is asynchronous)

Reset• In most microcontrollers there are available a few

reset sources:

– Power-on Reset. The MCU is reset when the supply

voltage is below the Power-on Reset threshold (VPOT)

– External Reset. The MCU is reset when a low level is

present on the RESET pin for longer than the minimum

pulse length

– Watchdog Reset. The MCU is reset when the Watchdog

Timer period expires and the Watchdog is enabled

– Brown-out Reset. The MCU is reset when the supply

voltage VCC is below the Brown-out Reset threshold

(VBOT) and the Brown-out Detector is enabled

Power-on Reset

External Reset

Brown-out Reset

Watchdog Reset

Electrical parameters

I/O ports

General I/O port structure

I/O port with internal pull-up

I/O port with push-pull

Introduction - 8051

Introduction

• Family of 8051 originates from Intel8051

microcontroller constructed in 1980

• 8051 microcontrollers were, for the long time,

the most popular microcontrollers on the

market

Introduction• One of the source of success is the fact that

8051 base microcontrollers are offered by

many vendors (e.g. Siemens, Infineon, Atmel,

Philips, Dallas Semiconductors, Analog

Devices)

• 8051 based microcontrollers are still very

popular because of backward compatibility

and because present constructions are much

more efficient than original ones

Introduction – block diagram

CPU

On-chip

RAM

On-chip

ROM for

program

code

4 I/O Ports

Timer 0

Serial

PortOSC

Interrupt

Control

External interrupts

Timer 1

Timer/Counter

Bus

Control

TxD RxDP0 P1 P2 P3

Address/Data

Counter

Inputs

Introduction - Architecture

• Main features:

– 8-bit CISC processor

– Modified Harvard architecture (instructions and

data on separate busses)

– 4 banks of 8 x 8b universal registers

– Instructions executed in 1, 2 or 3 instruction clock

cycles (12 clock pulses)

Introduction - Architecture

• Main features:

– 4kB of internal ROM

– 128B of internal SRAM

– four parallel ports P0..P3

– 1 x UART

– Two timers (one used for UART transmission)

– interrupt subsystem with priorities

PIC10 Sourc

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8051 - pinout

Sourc

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8051 - pinout• Main pins:

– RST – active high

– EA – External Access – logic „0” means execution

of program from internal ROM

– PSEN - Program Store Enable – OE for external

memory

– ALE - Address Latch Enable – signal used for

demultiplexing of data and address

8051 - registers

A

B

R0

R1

R3

R4

R2

R5

R7

R6

DPH DPL

PC

DPTR

PC

Some 8051 16-bit Register

Some 8-bitt Registers of

the 8051

Sourc

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8051 – Main producers

ChipCON (TI) – versions with internal wireless

communications blocks

Analog Devices – very good „Analog

microcontrollers” with embedded, high-quality,

analog-digital and digital-analog converters

8051 – Main producers

Dallas Semiconductors – very high performance

(33MIPS in comparison to original 1MIPS!!!);

excellent communication blocks (CAN, Ethernet)

NXP – a lot of „classical” models, power supply

current reduction, improved performance

8051 by ChipCON (TI)

8051 by ChipCON

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CC2430

• Main features:

– SoC chip – integrated processor and RF circuits

– 8051 CPU, 32MHz

– 8kB of SRAM

– 128kB Flash

– RF 2.4GHz, 802.15.4 transceiver

– Low supply voltage

– Very small component count

CC2430

Sourc

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8051 by Analog Devices

PIC12F615 – block diagram

ADuC 824

• Named „Analog microcontroller”:

– Main part are precision ADC’s and DAC’s

– Microprocessor is only an addition

• Fully integrated 24-bit data acquisition system

• Software compatible with 8052 processors

ADuC 824

Sourc

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ADuC 824

• Main features:

– High Resolution Sigma-Delta ADCs

• Two Independent ADCs (16- and 24-Bit Resolution)

• Programmable Gain Front End

• 24-Bit No Missing Codes, Primary ADC

• 13-Bit p-p Resolution @ 20 Hz, 20 mV Range

• 18-Bit p-p Resolution @ 20 Hz, 2.56 V Range

– Memory:

• 8kB Program Memory, 640 B Data Memory (Flash)

• 256B Data RAM

ADuC 824

• Main features:

– 8051-Based Core

• 8051-Compatible Instruction Set (12.58 MHz Max)

• 32 kHz External Crystal, On-Chip Programmable PLL

• Three 16-Bit Timer/Counters

• 26 Programmable I/O Lines

• 11 Interrupt Sources, Two Priority Levels

– Power

• Specified for 3 V and 5 V Operation

• Normal: 3 mA @ 3 V (Core CLK = 1.5 MHz)

• Power-Down: 20 uA (32 kHz Crystal Running)

ADuC 824

• Main features:

– On-Chip Peripherals

• On-Chip Temperature Sensor

• 12-Bit Voltage Output DAC

• Dual Excitation Current Sources

• Reference Detect Circuit

• Time Interval Counter (TIC)

• UART Serial I/O

• I2C®-Compatible and SPI® Serial I/O

• Watchdog Timer (WDT), Power Supply Monitor (PSM)

ADuC 824 – Main ADC structure

8051 by Dallas Semiconductors

PIC12F615 – Pinout

Sourc

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Sourc

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DS80C410

• 8-bit network microcontroller

• Many „connection” peripherals:

– 10/100 Mbs Ethernet

– 3 x serial ports

– CAN 2.0B controller

– 1-Wire Master

– 64kB SRAM for TCP/IP stack

PIC16 Sourc

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DS80C410

• Main features:

– High-Performance Architecture

• Single 8051 Instruction Cycle in 54ns

• DC to 75MHz Clock Rate (1MIPS/4MHz)

• Flat 16MB Address Space

• Four Data Pointers with Auto-Increment/Decrement

and Select-Accelerate Data Movement

• 16/32-Bit Math Accelerator

DS80C410

• Multitiered Networking and I/O

– 10/100 Ethernet Media Access Controller (MAC)

– Optional CAN 2.0B Controller

– 1-Wire Net Controller

– Three Full-Duplex Hardware Serial Ports

– Up to Eight Bidirectional 8-Bit Ports (64 Digital I/O

Pins)

DS80C410

• Integrated Primary System Logic

– 16 Total Interrupt Sources with Six External

– Four 16-Bit Timer/Counters

– 2x/4x Clock Multiplier Reduces Electromagnetic

Interference (EMI)

– Programmable Watchdog Timer

– Oscillator-Fail Detection

– Programmable IrDA Clock

DS80C410• Enhanced Memory Architecture

– Selectable 8/10-Bit Stack Pointer for High-Level LanguageSupport

– 64kBytes Additional On-Chip SRAM Usable asProgram/Data Memory

– 16-Bit/24-Bit Paged/24-Bit Contiguous Modes

– Selectable Multiplexed/Nonmultiplexed External MemoryInterface

– Merged Program/Data Memory Space Allows In-System Programming

– Defaults to True 8051-Memory Compatibility

DS80C410 – External memory merging

DS80C410 – arithemtic

coprocessor

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DS80C410 – Ethernet

DS80C410 – ROM functions

• Plenty useful functions can be found inDS80C410 ROM

• Many function categories, e.g.:

– Utility

– Memory managing

– Socket handling

– DHCP functions

– 1-Wire functions

– and many, many more….

DS80C410 – ROM functions

Thank you for your attention

References[1] www.infineon.com

[2] www.ti.com

[3] CC2430 documentation; www.ti.com

[4] ADuC845 documentation; www.analog.com

[5] www.maxim-ic.com

[6] DS80C410 documentation; www.maxim-ic.com

[7] http://www.ise.pw.edu.pl/impuls/emisy/80c517um.pdf

[8] http://www.atmel.com/images/doc2486.pdf