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Altera_Forum's avatar
Altera_Forum
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15 years ago

truncated value

Hi all, when I'm designing a simple mux: assign cmp_b = sel_ab1 ? (n+1'b1) : a; where N = 2 I got this warning: "Warning (10230): Verilog HDL assignment warning at determining...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

--- Quote Start ---

should I redefine as:

parameter N = 4'b0010 ?

--- Quote End ---

Right.

Then:

assign cmp_b = sel_ab1 ? (N+4'b0001) : a;

However these type of warnings are usually not a problem, provided you are aware of the size mismatch and its implications.

The compiler will truncate extra bits or pad with zero when missing (i.e. your "+ 1'b1" assignment on a 4bit value would be automatically converted into "+ 4'b0000")

Regards