Self-Test Descriptions,
Continued
The following tests are included:
Byte Mask test
Checks the byte mask signals that are generated by the CPU.
This test is performed on each page boundary. Once the test
is complete, all free memory is filled with AAh.
Memory test (forward)
Performs a read/compare/complement/write on the memory
in the forward direction. If a page is found to be bad, the
appropriate bit in the memory bitmap is cleared.
Memory test (reverse)
Starts at the last address to be tested and performs a read
/compare/complement/write on memory. If a page is found to
be bad, the appropriate bit in the memory bitmap is cleared.
Final Parity test
Fills all of memory with a pattern of 01h (an odd bit pattern)
to verify that the parity bit can be changed. This pattern is
read and verified. A parity error occurs if the parity bit is
not changed. The pattern 01010101h is the known state of
unused memory after power-up.
Refer to Appendix A for a list of the memory test error codes and
Appendix B for a list of the memory test diagnostic LED codes.
Floating Point
Unit Self-Test
(T 6)
The following tests are included:
Instruction tests
These tests are performed on the FPU. A failure occurs if
the instruction produces unexpected results or an unexpected
exception occurs during the execution of the instruction.
Continued on next page
5–23
