2.4 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. TBLPTRL
  3. TBLPTRH
  4. TBLPTRU
  5. TABLAT
  6. PRODH
  7. PRODL
  8. FSR0L
  9. FSR0H
  10. FSR1L
  11. FSR1H
  12. FSR2L
  13. FSR2H
  14. STKPTR
  15. INTCON0
  16. STATUS

API Documentation: CPU Registers Diagnostic Test