memcbit.doc(8) — Kubota Pacfic Computer Inc. (October 15, 1988)
NAME
memcbit.diag − Test check bits and refresh capability of memory card
DESCRIPTION
This test treats the ECC check bits in the memory as though it is ordinary memory. Various memory tests are performed to assure that all of the check bits are functional. ECC operations are disabled for the memory board that is being tested. Because this test modifies the contents of the ECC bits, it is necessary that at least two memory boards be installed. The first board (usually memory board ID 0) holds the program code. A memory board, other than board 0 is tested. Note that 16-way interleave cannot be active as this makes the two (or four) memory boards operate as a contiguous memory space and would prevent disabling the ECC on just one board. To prevent 16-way interleave from becoming active:
•If there are two memory boards in the system, and if both are exactly the same size, install one memory board in memory ID slot 0 (physical slot 3) and the other in memory ID slot 2 (physical slot 6).
•If there are two or four memory boards in the system and at least one is of a different capacity than the others, 16-way interleave will not be selected.
•If there are three memory boards in the system, 16-way interleave will not be selected.
DETAILS
none required.
BOARDS THAT MUST BE INSTALLED
This test needs a CPU card, and at least two memory cards. The memory cards must not be operating in 16-way interleave. The test reports problems, such as only one memory card found or if 16-way interleave is on with more than one card installed.
SPECIAL COMMAND LINE PARAMETERS
None
MENU ITEMS SPECIFIC TO THIS TEST
cbSelect the Check Bit test menu.
| wr | For 2 MegaWords, write memory with zeros and read back the value. |
| sd | Perform a walking one, then a walking zero test on the check bits. |
| ma | Perform memory testing by writing then reading a pattern, then its complement, on the ECC bits. |
rtSelect the Refresh Test menu
| vr | Veryify memory function with refresh active. |
| dr | Disable refresh, wait, then check that at least one memory location in each bank develops an error due to refresh being disabled. |
| db | Set double refresh, exercise the memory, and verify that double refresh is functioning. |
dmDisplay Memory board data
INTERPRETING THE ERROR CODES
The following errors may be generated by this test. (The actual error wording may differ, however the type of error is as summarized here.)
101Memory does not appear to be fully populated to four banks of memory on a specific card. When "gang mode" (currently not available in this test) is selected, there must be Four banks of memory on each card.
191Unable to turn off refresh on a particular memory card’s interleave control.
Unable to write the R Bus Status Register with the memory card configuration for a particular memory card.
Other Errors
This test will refuse to run if there is only one memory card or if 16-way interleaving is active. Each condition is associated with a reason-I-did-not-run message.
September 02, 1992