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Altera_Forum
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15 years ago

Interfacing with narrower width of slave

Hi I have a question regarding to interfacing with narrower or wider width of slave. As we know, our Nios II is 32-bit width. To perform a read/write to a slave, says a 16-bit memory, how should this...
Altera_Forum's avatar
Altera_Forum
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15 years ago

IOWR_32DIRECT() probably maps down to the correct instruction :-)

If it is 'normal' memory, you'll have to support byte enables - otherwise single byte writes won't work, even for a 16bit write you'll see two writes one will have neither byte enable asserted!

For memory mapped io buffers it is usually best to create a 32bit slave that hard-wires d16-31 to zero for reads.