Motorola MVME2300 Series User Manual
Page 217
Software Considerations
http://www.motorola.com/computer/literature
3-55
3
10. Make sure that no other devices respond in the range from
$00000000 to $40000000.
Then, for each block:
1. Set the block’s base address to $00000000.
2. Enable the block and make sure that the other three blocks are
disabled.
3. Set the block’s size control bits. Start with the largest possible
(1024MB).
4. Write differing 64-bit data patterns to certain addresses within the
block. The data patterns do not matter as long as each 64-bit data
pattern is unique. The addresses to be written vary depending on the
size that is currently being checked and are specified in
.
shows how PowerPC addresses correspond to DRAM
row/column addresses.
5. 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 the block is
currently programmed.
If any of the addresses do not match exactly, then the amount of
memory is less than that for which it is currently programmed.
Sizing needs to continue for this block by programming its control
bits to the next smaller size and repeating steps 4 and 5.
6. If no match is found for any size, then the block is unpopulated and
has a size of 0MB.