2.2.2. Bitmap mode

In bitmap mode, you can identify all failing locations in a RAM. Each time a failure occurs, the controller stops executing the current test and waits for you to begin shifting out the data log as Figure 2.11 shows.

Figure 2.11. Start of bitmap data log retrieval


After you finish shifting and drive MBISTDSHIFT LOW, the controller then resumes testing where it stopped as Figure 2.12 shows. This process continues until the test algorithm completes. A fault can cause a failure to occur several times during a given test algorithm. The fault might be logged multiple times depending on the number of reads performed by the algorithm and the exact nature of the fault.

Figure 2.12. End of bitmap data log retrieval


Loading a new instruction resets bitmap mode.

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