[U-Boot-Users] DDR SDRAM in DIMM module for Yosemite-like PPC440EP board.

[Leonid]

Hi:

I'm trying to port u-boot for "Yosemite-like" board with AMCC PPC440EP
CPU. The difference between this board and Yosemite itself is that it
has 4 128M banks of DDR SDRAM instead of 2 and (which is probably more
important) these chips are on DIMM module. I think I've configured
everything correct, see SDRAM registers block from BDI2000 config file
below:

; Setup SDRAM Controller (DDR SDRAM)
WDCR    0x10    0x00000082      ;Select SDRAM0_CLKTR
WDCR    0x11    0x40000000      ;CLKTR: Advance 90 degrees
WDCR    0x10    0x00000080      ;Select SDRAM0_TR0
WDCR    0x11    0x410a4012      ;TR0:
WDCR    0x10    0x00000081      ;Select SDRAM0_TR1
WDCR    0x11    0x80800819      ;TR1:
WDCR    0x10    0x00000040      ;Select SDRAM0_B0CR
;;WDCR  0x11    0x000a4001      ;B0CR: 128M first bank, start 0x0, 13x10
WDCR    0x11    0x000a6001      ;B0CR: 128M first bank, start 0x0, 13x11
WDCR    0x10    0x00000044      ;Select SDRAM0_B1CR
;;WDCR  0x11    0x080a4001      ;B1CR: 128M second bank, start
0x08000000, 13x10
WDCR    0x11    0x080a6001      ;B1CR: 128M second bank, start
0x08000000, 13x11
WDCR    0x10    0x00000048      ;Select SDRAM0_B2CR
WDCR    0x11    0x100a6001      ;B2CR: 128M third bank, start
0x10000000, 13x11
WDCR    0x10    0x0000004C      ;Select SDRAM0_B3CR
WDCR    0x11    0x180a6001      ;B3CR: 128M forth bank, start
0x18000000, 13x11
WDCR    0x10    0x00000030      ;Select SDRAM0_RTR
WDCR    0x11    0x04080000      ;RTR:
WDCR    0x10    0x00000020      ;Select SDRAM0_CFG0
WDCR    0x11    0x36000000      ;CFG0: 32bit, PMU disable, DIMM enable.
WDCR    0x11    0x86000000      ;CFG0: enable SDRAM & DIMM
WDCR    0x10    0x00000021      ;Select SDRAM0_CFG1
WDCR    0x11    0x00000000      ;CFG1

However MRSC bit of SDRAM0_MCSTS register never gets set meaning SDRAM
controller has never successfully completed the Mode Register Set
Command. Attempts to read memory also fail (from BDI2000 itself and from
u-boot where I've modified memory configuration of course).

That can be HW problem of course, but may be somebody can suggest any
configuration problem leading to similar symptoms? Any ideas at all?

Thanks,

Leonid.