number of banks, rows and columns the SDRAMC is programmed to access
to determine the RAM size for the board, rather than hard-wiring it to
be 32MB. My company's board with 64MB now probes correctly, as does
the KB9202 with only 32MB. This means that to detect the right memory
size, our boot loader must correctly initialize these values. This is
a fairly safe assumption because the boot loader has to initialize
SDRAM already, and it isn't really possible to change this register
after we've accessed SDRAM.