SImultaneous FIFO load/store

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PiWy_2406846
Level 3
Level 3

Hello,

   

assume F0 is in dynamic, edge triggered mode and is controlled by UDB, (stores from A0). It contains [1, 2, 3, 4], A0=5. Now, let there be a datapath sequence of states

   

PASS A0, (A0 WR SRC = F0)

   

ADD A0, A0

   

and the FIFO write strobe generates a rising edge when control goes to the ADD. There are two possible scenarios in that state:

   

a) F0 = [2, 3, 4, 5], A0 = 1 (read and write were merged: I'd like this to happen)

   

or:

   

b) F0 = [2, 3, 4], A0 = 1 (because: A0 is first written to a full FIFO, so ignored, then the FIFO is read into A0)

   

or:

   

c) undefined.

   

Which one will happen? I can check it on a real device, but I don't consider it a proof of anything -- is there a documentation backup for that behavior?

   

    Best regards,

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