Toshiba satellite A20 series Maintenance Manual page 125

3.5 Memory Test
Subtest 04 Cache Memory
To test the cache memory, a pass-through write-read comparison of '5A' data
is run repeatedly to the test area ('7000':'Program' size to '7000':'7FFF' (32
KB)) to check the hit-miss ratio (on/off status) for CPU cache memory. One
test takes 3 seconds.
Number of misses < Number of hits → OK
Number of misses ≥ Number of hits → Fail
Subtest 05 L2 Cache Memory
To test the L2 cache memory, a test similar to that for the cache memory is
performed.
Subtest 06 Stress
The conventional memory is provided with a write/read buffer (size 1b30 h)
and creates write data in the write buffer. Subsequent to 1 MB, the data is
written in the write buffer and is read into the read buffer, followed by a data
comparison up to the maximum memory size.
Satellite A20 Maintenance Manual (960-444)
3 Tests and Diagnostics
3-13