Honored ContributorHello,
i have a multicycle custom instruction which need to receive a data from its conduit port (the signal is imported from an other processor). i want to know if this custom instruction can read the data even if clk_en is null (data can come when the custom instruction is not called by the nios ide). Thanks.
Honored Contributorno one to answer to my question?
please help meHonored ContributorNot sure what your problem is.
IIRC the 'clk_en' signal is basically an indication that the specific custom instruction is being executed. There may be a requirement that some of the output signals not be asserted unless clk_en is asserted - in order to avoid messing up other custom instructions. What you do with any other signals is only constrained by your imagination (and the time available to execute the instruction).Honored ContributorYour custom instruction should be written to ignore dataa, datab, and n when clock enable is low.
Honored ContributorHonored ContributorAnything on the 'result' port is (or at least should be!) ignored except during the final clock cycle of the instruction.
There is nothing to stop you latching the data and using it when the instruction is being executed - but that latch might, more properly, be considered as path of the external logic the custom interface in connected to.
