siva_7517
Full Member level 2
verilog signed multiplier fixed-point
Hi,
I am currently doing a FFT for 8 point. Basically, I
have problem in fixed-point multiplication because
there is a extended sign bit before the adding. I have
no idea on how to write this in verilog code.
I try with this verilog code :
assign A = B*C
but it giving a wrong answer.
the example of calculation is shown below:
-----------------1.110 ____________ -0.25 B
--------------x 0.110 ____________ 0.75 C
-----------------------
---------------- 0000
------------111110------------------->extended sign bit
------------11110--------------------->extended sign bit
----------+0000
-----------------------------
----------11110100 _______________-0.1875 A
When we do a fixed point multiplication there is extra sign bit in inserted before the adding is done. I have difficulty on how to intepret this in verilog.thanx
Siva
Hi,
I am currently doing a FFT for 8 point. Basically, I
have problem in fixed-point multiplication because
there is a extended sign bit before the adding. I have
no idea on how to write this in verilog code.
I try with this verilog code :
assign A = B*C
but it giving a wrong answer.
the example of calculation is shown below:
-----------------1.110 ____________ -0.25 B
--------------x 0.110 ____________ 0.75 C
-----------------------
---------------- 0000
------------111110------------------->extended sign bit
------------11110--------------------->extended sign bit
----------+0000
-----------------------------
----------11110100 _______________-0.1875 A
When we do a fixed point multiplication there is extra sign bit in inserted before the adding is done. I have difficulty on how to intepret this in verilog.thanx
Siva