Sizing SDRAM memory with Geode

Hi!

I am using AMD Geode SC1100 processor in my project and I am developing a boot loader for it. Unfortunately I cannot determine correctly SDRAM size. I am using AMD Geode GX1 Processor Single Chip Processors XpressROM SDRAM Sizing Algorithm from AMD web page for developers. It works fine with memory 128MB and above but hangs if less memory is used. The problem seems to be DIMM0 Module Banks bit (bit nr. 14) in MC_BANK_CFG register. If this bit is clear (1 module bank is selected) then program execution stops (probably execution jumps to memory location where is no code?) after calling DO_REFRESH subroutine (setting and clearing RFHSTST bit in MC_MEM_CNTRL1). If this bit is set, then DIMMs that have 2 module banks works fine. Any ideas?

TIA, Madis

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Madis
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