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MPC8260a 60x SDRAM external address multiplixer in 60x-compatible mode?

Question asked by meng junling on Sep 24, 2014
Latest reply on Oct 15, 2014 by meng junling

Hi,everyone, I use MPC8260A in my design, now I encounter some problems when debugging. When I access SDRAM in CodeWarrior unsing USB-TAP, an error message "writemem on target failed at address 0x400, size 0x1000". But when I only access 0x100 bytes, it's ok.  I measure signal waveform using DPO,  the timing is correct.

Sometimes I refresh data in codewarrior, the memory data will change. It seems the refresh timing is wrong.

MPC8260 is in 60x-compatible mode,66Mhz bus clock . 60x SDRAM is configured 32bit-port ,128MB(13 rows, 10cols,4 bank, 512Mb density), page-based mode.   So 60x SDRAM address is latched and muxed externally. Please help me to check the address connection?


BR: MS = 60x SDRAM, Port size = 32bit

OR: BPD = 01(4 bank), row start = A5, row number = 13

PSDMR:PBI = 1, SDAM = 100, BSAM = 010(A14-A16)


SDRAM BA[1:0] using dedicated pin BNKSEL[1:2].


  row         bank-sel         col

A[5:17],  A[18:19],   A[20:29]



SDRAM pins: BA1    BA0              A12    A11     A10     A9----A0


Phsical  :      A15    A16               A17    A18     A19     A20---A29


ACT    :      BNKSEL1 BNKSEL2    A5      A6     SDA10  A9--- A17

R/W     :     BNKSEL1 BNKSEL2     --       --       AP       A20--A29  

60x address is muxed (using IDTQS3257):