MPC8248 IDMA PCI burst

Arun Roy ArunR at
Sat Feb 14 04:38:19 EST 2009


I am having some problem with the PCI burst using the MPC8248 IDMA feature. I can get a continuous burst of 2k when transferring data from the system memory to the PCI direction but in the other direction (i.e. PCI to system memory) the PCI burst is fragmented with 32 bytes of fragment.  I have verified that the Prefetch bit is set in the POCMR register.

Here are my settings :

DCM : DMA_WRAP=101, SINC=1, DINC=1, S/D=00

STS: 2016

SS_MAX: 2016

BUF_INV: 2048

DTS: 2016

Transfer buffer size is 2048 bytes

BD flags : V=1, W=1, I=1, L=1, BD Len = 1024

Any help will be appreciated.



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