Efficient Embedding of Deterministic Test Data Mudassar Majeed 1, Daniel Ahlström 1, Urban...
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Transcript of Efficient Embedding of Deterministic Test Data Mudassar Majeed 1, Daniel Ahlström 1, Urban...
Efficient Embedding of Deterministic Test Data
Mudassar Majeed1, Daniel Ahlström1, Urban Ingelsson1,
Gunnar Carlsson2 and Erik Larsson1
1Department of Computer and Information Science, Linköping
University, Sweden
2Ericsson AB BU Networks SE-164 80 Stockholm
Sweden
2
Purpose Printed Circuit Boards (PCBs) include an increasing number of
integrated circuits (ICs), often of the same type
Example:
Ericsson telecommunication systems contain PCBs with 36 ICs where 4 ICs are of type A, 8 ICs of type B, 8 ICs of type C and 16 ICs of type D
In-field testing is needed due to harsh environment
For in-field test, the problem is to deliver test data to the system
Straight forward solution is to store test data in the system
Drawbacks:
High memory requirements
Inflexibility in applying different tests
The proposed solution uses an embedded test controller to manipulate test data by exploiting structural information of the system
Benefits: Reduces memory requirements and provides flexibility
Efficient Embedding of Deterministic Test Data
3
Outline Introduction
Proposed Solution
Experiments and Results
Conclusions
MARKERINGSYTA FÖR BILDER
När du gör egna slides, placera bilder och andra illustrationer inom dessa fält. Titta gärna i ”baspresentationen” för exempel på hur placeringen kan göras.
4
Need for Remote System Test
System at Remote Location
Flexibility in applying commands Embedded test solution
Test Engineer at Office
Comm
and 1
:
Test A
ll Com
ponents
Comm
and 2
:
Test O
nly C
omponen
t A
Introduction
5
Embedded Test Solution
Command 1:
Test All Components
Command 2:
Test Only Component A
Embedded
Test
Solution
PCB
Components
A B B
Test
Data
Test
Resp.
Introduction
6
IEEE 1149.1 Standard
ICs connected serially (IEEE 1149.1)
B BA
IEEE 1149.1 Standard for PCB testing Supports testing core logic Instructions INTEST, BYPASS
Introduction
7
IC Under Test Using IEEE 1149.1 Standard
IEEE 1149.1
1.IR-scan: Set instruction
2.DR-scan: Apply (execute)
IR-scan defines the length of the 1149.1 chain
Introduction
A
BYPASS A
Bypass component A
1 bit
A
INTEST A
Test component A
4 bits
Stimuli:
Instruction:
INTESTBYPASS
8
System Under Test Using IEEE 1149.1 Std.
B BA
Command 1:
Test All Components
Command 2:
Test Only Component A
INTEST A INTEST B INTEST B
B BA
INTEST A BYPASS B BYPASS B
Introduction
Test Vectors
9
Naive Embedded Test Controller
Embedded Test Solution
CPU
Memory
Command 1:
Test All Components
(INTEST A INTEST B INTEST B)
Command 2:
Test Only Component A
(INTEST A BYPASS B BYPASS B)
High memory requirements and inflexibility in applying the tests
Introduction
10
Outline Introduction
Proposed Solution
Experiments and Results
Conclusions
MARKERINGSYTA FÖR BILDER
När du gör egna slides, placera bilder och andra illustrationer inom dessa fält. Titta gärna i ”baspresentationen” för exempel på hur placeringen kan göras.
11
Key Idea
Embedded Test Solution
Concatenator
Memory
Command 1: Test All Components INTEST A INTEST B INTEST B
Command 2:Test Only Component A INTEST A BYPASS B BYPASS B
StructuralInformation
Provides flexibility in applying the tests
Type A
Type B
Command
Command 1:1 2
3
Proposed Solution
Command 2:
12
1. Memory Requirements
MemoryMemory
Reduces memory requirements
Naive approach Proposed concatenation approach
Comparison
Proposed Solution
13
2. Structural Information
B BA
Structural Information
- Types of components
- Order of components in the system
- Instruction Register Length
- Data Register Length
- Instructions
Proposed Solution
14
3. Concatenator
B BA
Steps for a given command:
1. Read structural information
2. Read component specific test stimuli
3. Concatenate the stimuli
4. Scan in instruction vector (if required)
5. Scan in and apply test vector
6. Scan out test response
7. Compare with expected response
8. If exit condition met, then terminate
9. Else repeat step 2
Proposed Solution
15
Outline Introduction
Proposed Solution
Experiments and Results
Conclusions
MARKERINGSYTA FÖR BILDER
När du gör egna slides, placera bilder och andra illustrationer inom dessa fält. Titta gärna i ”baspresentationen” för exempel på hur placeringen kan göras.
16
Objectives
To show that the approach works:
We used a PC as test controller and an FPGA as system under test
To see how memory requirements are reduced:
Naive Approach vs Proposed Concatenation Approach (for test command: “test all components”)
We created systems using industrial circuits as ICs
Experiments and Results
% Reduction in
Memory Requirements=
17
Industrial Circuits
CircuitLength of Test Patterns (bits)
Number of Test Patterns
Test Data Volume (MBs)
ckt-1 11256 3768 5.51ckt-2 22216 2636 6.98ckt-3 9628 4927 5.65ckt-4 43414 1528 7.91ckt-5 26970 4899 15.75ckt-6 80000 2859 27.27ckt-7 20000 18027 42.98ckt-8 110000 18142 237.9
Z. Wang and K. Chakrabarty. Test data compression for IP embedded cores using selective encoding of scan slices. In Proc. International Test Conference (ITC), pp. 581--590, 2005.
Experiments and Results
18
Industrial Circuits
Experiments and Results
# of Multiplications
2
3
20
ckt-1 ckt-2 ckt-3 ckt-4 ckt-5 ckt-6 ckt-7 ckt-8
Design
2
3
20
2
3
20
1
2
8
Set
19
Results
Experiments and Results
Number of Multiplications
Per
cent
age
Red
uctio
n in
Mem
ory
Req
uire
men
ts
Average
Set 1 (ckt-1)
Set 2 (ckt-2)
Set 3 (ckt-3)
Set 4 (ckt-4)Set 5 (ckt-5)
Set 6 (ckt-6)
Set 7 (ckt-7)
Set 8 (ckt-8)
Set 7 (ckt-7)
Set 8 (ckt-8, 237.6 MBs)
Average
Set 1 (ckt-1)
5.51
6.98
5.65
7.91
15.75
27.27
42.98
237.9
MBs
20
Conclusions Printed Circuit Boards (PCBs) include an increasing number of
integrated circuits (ICs), often of the same type
Systems fail in operation and require in-field testing
Test data volume requires huge memory
The proposed solution exploits,
Structural Information of the system
The fact that multiple components of the same type require same test data
The test data manipulation via an embedded test controller
The reduction in memory requirements depends upon the number of components of the same type
Example:
Ericsson telecommunication systems contain PCBs with 36 ICs where 4 ICs are of type A, 8 ICs of type B, 8 ICs of type C and 16 ICs of type D