Xilinx ISE 8.1.03 returns 225 in pre and post simulation (ISE simulator). Are you running this on hardware or simulation? Alan Nishioka
Read the full replyIn the following module, module mult (output reg[7:0] z, input [3:0] a); always @* begin z = a*a; end endmodule
ModelSim returns 225 when a is 15, but the Xilinx implementation on a Spartan3 returns a 1 (-1 * -1). Does anybody know why Xilinx ISE is interpreting the four bit numbers as signed numbers rather than unsigned?
-Gary
Xilinx ISE 8.1.03 returns 225 in pre and post simulation (ISE simulator). Are you running this on hardware or simulation?
Alan Nishioka
I did not simulate in Xilinx - it was implemented on a Digilent Spartan 3 board.
-Gary
What results do you get for all the other numbers? (8 * 8, for example)
Alan Nishioka
Search for the thread 'multiplier madness' from a couple of weeks ago.
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