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Altera_Forum
Honored Contributor
Honored ContributorFlash read causes two reads
I have the Stratix III development kit with the 512-Mbit Intel part on it. My command writes appear to be correct, looking at it with SignalTap. I write to the base address a command such as ...
Altera_ForumHonored Contributor
Honored Contributorthis a behaviral of the avalon switch fabric, an old bug/problem/feature
your master (niosII) is 32 bit your slave (ext flash) 16bit unfortunately the avalon switch fabric fetches 2 16bit values to get 32 bit yes this is not needed as you read only 16 bit but it is implemented that way. this gets anoying when the external component does something upon a read like all external profibus chips that i am aware of, a read of certain addresses are recognized and clear other bits, hard to find. normaly these wasted read cycles do not disturb so you can ignore them a 16 bit write does only 1 16bit cycle if you realy want to get rid of the additional cycle you will need to insert some kind of logic that monitors the byteenable as they tell you the truth what byte is realy needed.
