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Altera_Forum
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11 years ago

Avalon 8 bit with Nios 32 bit possible?

It is possible to create a component (ex. UART) with avalon MM slave interface with 8 bit data width and use it with Nios II with 32 bit bus? I tried and compile fine but Nios II don't start on re...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
11 years ago

Attached is updated waveform with the NIOS data master Avalon signals expanded, where you'll see it is correctly issuing reads with 1,2,4 bytes enabled; the bus width adapter isn't doing much if anything.

Where do you see that the NIOS is definitely documented as always doing 32-bit access? The instruction set reference (ldbuio, ldhuio, ldwio) is pretty clear on what it is advertising, and I tend to agree with it based on my experiences.