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Altera_Forum
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15 years ago

[bug report QII 9.1] HDL srff primitive incorrect implemented

Hi. i`m not know where to post an QII issues, therefore try to post it here.

My shema used srff primitive. in created HDL file his primitive post like:

always @(posedge clock) begin

q <= ~q&s | q&~r

end

this behaviour is incorrect, and it easy to see. if trigger states in undefined state (q == X), it cant be stated in valid state any how, not matter what values on S or R inputs. (lpm implementation of srff is valid.)

do not use srff primitive!!!!.
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