IDMA IN MPC82XX (i.e mpc8272)

Jonathan Qiang jqiang at haliplex.com
Wed Nov 8 13:04:39 EST 2006


Any one who has any experience when using IDMA on mpc82xx? 
Currently, the status what I have got is, memory-to-memory mode, both
Data bus had been set to 60x-bus, which means DDTB and SDTB are working
on 60x-bus. if set DMA_WRAP in DCM as 64-byte, SS_MAX,STS and DTS in
(IDMA Parameter RAM) all to 32 Bytes, there working good!
But if set DMA_WRAP more than 64-byte(i.e 256-bytes) ,SS_MAX,STS and DTS
in (IDMA Parameter RAM) all to 7*32 Bytes when WRAP = 256 . then got
some issues:
1. some bytes in a packet had been changed oddly. for example if  some
bytes in the packet is "20 0f 17 2c...." after 
IDMA transmission , the bytes will be changed as "20 1d 17 2c", there is
a slightly different with "17" and "1d".
2. some bytes had been swapped , for example "20 0f 17 2c" , after
transmission , the bytes in packet was "2c 17 0f 20".
Any ideas? 
Is this the cache issue? I had enabled the snooping
 
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