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Altera_Forum
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12 years ago

Avalon MM/ST/SGDMA Byte ordering

Hi, I'm using the SGDMA IP core to transfer some data from Avalon MM interface to Avalon ST interface and back to Avalon MM. Everything 32 bit width. NIOS->Memory-> Avalon MM -> SGDMA...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

I had a look at our old code and in fact we did the endian conversion in software. Indeed the SGDMA can't be directly configured to process 32-bit words and only works with bytes. You will either have to work with big endian values in software, or add you own custom stream component that will shift the bytes around to get 32-bit values as they are seen by the CPU.