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Altera Avalon MM Read Master Template: max transfer length of 20 bytes?

Honored Contributor II

Hi everyone, 


I have sucessfully integrated the Altera Avalon MM Read Master template. However, this only works properly up to the length of 20. (word size is 32 bit) 


When I define the transfer length to be 24, i.e. 6 words, then there are only 5 dataavailable assertions with 5 buffered data. What I find interesting is, that the signal early_done does get asserted, meaning the last read is actually posted, but the signal done is never asserted, so somehow the result cannot be returned. 


I already used a FIFO of size 64, so should be big enough I think. 


Is this a known issue? Or anyone an idea what the problem could be? 


Best regards, 

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Honored Contributor II

Hi, it will be faster to write Avalon MM Read Master by yourself than try debugging these templates. There are 3 parts here: send read addresses, react on waitrequest and collect incoming data on the bus.

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