Direct SPU to SPU DMA requests on the Cell Processor?

Question

Normal DMA requests on the Cell happen between the SPUs and the PPU. However, I have read that it is possible to set up DMA directly between SPUs. Anyone have any idea how this is accomplished?

score 2 · Accepted Answer · answered May 01 '09 at 06:39

Have a look at spe_get_ls(). This will help you to setup a list of effective addresses that you can use to transfer data between local stores. You may need some management to map spe identifiers to physical SPUs.

score 0 · Answer 2 · answered Oct 30 '09 at 12:10

The trick is essentially what Chris said. The local store of one SPE is memory-mapped into the PPE's memory space. And then you just perform a regular DMA transfer from the other SPE to that address on the PPE.

I'm sorry I don't have the exact code for this. It's been a year or so since I had to do any of this. :)

Direct SPU to SPU DMA requests on the Cell Processor?

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