IBM xSeries 380, Hardware Maintenance Manual

Page: 37 / 324

Diagnostics
27
You can specify the beginning and ending memory locations memory in the Memory
Start and Memory End fields. If the displayed percentage is less than 100%, the
percentage is the amount of system memory between the Memory Start and Memory
End values tested.
You can also specify the size of the bit pattern that is written to memory in this test in
the Pattern Size field. The bit pattern sizes are 8 bits, 16 bits, 32 bits, or all bit pattern
sizes. The default is 8 bits. This test writes a rolling zero pattern to all memory
locations. The pattern is constructed so that only one bit of each byte is 0 at any time.
Random memory test
The Random Read/Write Test uses five test routines to write a random bit pattern to a
randomly-selected DRAM system memory location and read the same memory
location, looking for the same bit pattern that was written. The test cycles through
each of the five routines. The routines are:
To run the test, select Memory and Random Memory Test and press <Enter>. A list of
parameters appears:
Subtest Description
Initialize Randomize Test Begin the random memory test.
Validate Randomize Test Validate information found in the random memory test.
Initialize Random Increment Test Begin the incremental random memory test.
Random Increment Read/Write Begin the incremental random read/write memory test.
Validate Memory Validate information found in the random read/write
memory test.