MVME5100 Single Board Computer Programmer's Reference Guide

2. For each of the Blocks A through H:
Software Considerations
a. Set the block’s base address to $00000000. Refer to the sections
titled SDRAM Base Address Register (Blocks A/B/C/D) and
SDRAM Enable and Size Register (Blocks E,F,G,H).
b. Enable the block and make sure that the other seven blocks are
disabled. Refer to the same sections as referenced in the previous
step.
c. Set the block’s size control bits. Start with the largest possible
(512MB). Refer to the same sections as referenced in the
previous step.
d. Wait for at least one SDRAM refresh to complete.
e. Write a unique 64-bit data pattern to each one of a specified list
of addresses. The list of addresses to be written varies depending
on the size that is currently being checked. The address lists are
shown in the table below.
f. Read back all of the addresses that have been written.
If all of the addresses still contain exactly what was written, then
the block’s size has been found. It is the size for which it is
currently programmed.
If any of the addresses do not contain exactly what was written,
then the block’s memory size is less than that for which it is
programmed. Sizing needs to continue for this block by
programming its control bits to the next smaller size, waiting for
at least one refresh to complete, and repeating steps e and f.
g. If no match is found for any size then the block is unpopulated
and has a size of 0MB. Its size should be programmed to 0.
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