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Digital Signal Processors (DSP)
C6000 Single Core DSP
C64x Single Core DSP Forum
6482 DMAs take longer when accessing external memory... SCR priorities?
I'm using a 6482. I have an FPGA connected via EMIFA (synchronous). I have external RAM connected via DDR2 Memory Controller.
I have a high priority thread that processes an interrupt from the FPGA and starts a DMA transfer from the FPGA to internal memory.I have a low priority thread that chugs on the data and uses external RAM.
It appears that the DMAs from EMIF take longer to complete when the low priority thread is running.I assumed I needed to adjust the priorities on the SCR.But in sprs246k section 4.4, it says the default priority has the EDMA3 as the highest priority.
Other ideas? Something I am missing?
I think I have tracked down the problem.
I added the compiler option "-mi 1000" and the problem seeems to go away.
I assume my low priority thread was getting in a tight loop and holding off interrupts...
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