1. Memory Test

2. - Stuck-at faults, - Transition faults, - Coupling faults, - Decoder faults, - Read/Write Logic faults. Types of faults afecting RAMs:

3. Built-In Self Test (BIST) Introduction for Memory Test

4. a) Mscan Test

5. b) Marching Test

6. c) Transparent BIST Test on the field Transparent Built-In Self Test is a test algorithm that is periodically executed on the field in order to verify the integrity of large amounts of critical data stored on mass memory systems

7. Main characteristics: 1)Minimum area overhead 1) Minimum area overhead: this approach is one of the best choices found in the literature in terms of area overhead and types of faults detected in memory structures. E.g., authors claim an area overhead of 1.2% due to the inclusion of Transparent BIST in a 128Kbytes X 8bytes SRAM (this value decreases as the RAM size increases). c) Transparent BIST Test

8. Main characteristics: 2)High capability of fault detection 2) High capability of fault detection: by indicating the occurrence of stuck-at faults, transition faults,coupling faults, decoder faults and read/write logic faults. c) Transparent BIST Test

9. Main characteristics: 3)Short “down times” 3) Short “down times”: that are periodically required to check the functionality of mass memory systems used in real-time applications. The Transparent BIST approach presents the incomparable advantage of preserving the contents of the RAM memory after testing. Thus, this approach is very suitable for periodic testing since we do not need to save the memory contents before the test session and to restore them at the end of this session. c) Transparent BIST Test

10.  execution time c) Transparent BIST Test Table 1. Transparent BIST Algorithm

11. The data read during execution of sequences S1’ through S4’ of the Signature Prediction Algorithm (Table 1) are sometimes inverted in order to match the data read during the execution of sequences S1 through S4 of the Transparent BIST Algorithm (Table 1).  execution time c) Transparent BIST Test Table 2. Signature Prediction Algorithm S1 S2S3S4