TailCorr/rtl/DW02_mult.v

100 lines
3.0 KiB
Verilog

////////////////////////////////////////////////////////////////////////////////
//
// This confidential and proprietary software may be used only
// as authorized by a licensing agreement from Synopsys Inc.
// In the event of publication, the following notice is applicable:
//
// (C) COPYRIGHT 1994 - 2018 SYNOPSYS INC.
// ALL RIGHTS RESERVED
//
// The entire notice above must be reproduced on all authorized
// copies.
//
// AUTHOR: KB WSFDB June 30, 1994
//
// VERSION: Simulation Architecture
//
// DesignWare_version: 714fe7a9
// DesignWare_release: O-2018.06-DWBB_201806.3
//
////////////////////////////////////////////////////////////////////////////////
//-----------------------------------------------------------------------------------
//
// ABSTRACT: Multiplier
// A_width-Bits * B_width-Bits => A_width+B_width Bits
// Operands A and B can be either both signed (two's complement) or
// both unsigned numbers. TC determines the coding of the input operands.
// ie. TC = '1' => signed multiplication
// TC = '0' => unsigned multiplication
//
// FIXED: by replacement with A tested working version
// that not only doesn't multiplies right it does it
// two times faster!
// RPH 07/17/2002
// Rewrote to comply with the new guidelines
//------------------------------------------------------------------------------
module DW02_mult(A,B,TC,PRODUCT);
parameter integer A_width = 8;
parameter integer B_width = 8;
input [A_width-1:0] A;
input [B_width-1:0] B;
input TC;
output [A_width+B_width-1:0] PRODUCT;
wire [A_width+B_width-1:0] PRODUCT;
wire [A_width-1:0] temp_a;
wire [B_width-1:0] temp_b;
wire [A_width+B_width-2:0] long_temp1,long_temp2;
//-------------------------------------------------------------------------
// Parameter legality check
//-------------------------------------------------------------------------
initial begin : parameter_check
integer param_err_flg;
param_err_flg = 0;
if (A_width < 1) begin
param_err_flg = 1;
$display(
"ERROR: %m :\n Invalid value (%d) for parameter A_width (lower bound: 1)",
A_width );
end
if (B_width < 1) begin
param_err_flg = 1;
$display(
"ERROR: %m :\n Invalid value (%d) for parameter B_width (lower bound: 1)",
B_width );
end
if ( param_err_flg == 1) begin
$display(
"%m :\n Simulation aborted due to invalid parameter value(s)");
$finish;
end
end // parameter_check
assign temp_a = (A[A_width-1])? (~A + 1'b1) : A;
assign temp_b = (B[B_width-1])? (~B + 1'b1) : B;
assign long_temp1 = temp_a * temp_b;
assign long_temp2 = ~(long_temp1 - 1'b1);
assign PRODUCT = ((^(A ^ A) !== 1'b0) || (^(B ^ B) !== 1'b0) || (^(TC ^ TC) !== 1'b0) ) ? {A_width+B_width{1'bX}} :
(TC)? (((A[A_width-1] ^ B[B_width-1]) && (|long_temp1))?
{1'b1,long_temp2} : {1'b0,long_temp1})
: A * B;
endmodule