1.4 CPU Register Test

Test Name: CPU Register Test.

Acceptable Measure (Annex. H): Functional Test (H.2.16.5)

Purpose of test: Detect stuck bits in the CPU registers.

Description: CPU registers are tested for stuck bits and coupling faults between each of the bits inside the individual registers but not between registers.

The basic algorithm works as below:

The test can be done successively doing a write, read and check of 0x55 and 0xAA value into the CPU registers. The register is saved into RAM before the test is performed and restored after the test is done.

• Registers should be tested in following order:
  1. WREG
  2. WREG_SHAD
  3. BSR_SHAD
  4. FSR0L_SHAD
  5. FSR0H_SHAD
  6. FSR1L_SHAD
  7. FSR1H_SHAD
  8. BSR
  9. FSR

API Documentation: CPU Register Diagnostic Test