OpenFPGA/openfpga_flow/openfpga_cell_library/verilog/mult_36x36.v

36 lines
1017 B
Verilog

//-----------------------------------------------------
// Design Name : mult_36x36
// File Name : mult_36x36.v
// Function : A 36-bit multiplier which can operate in fracturable modes:
// 1. four 9-bit multipliers
// 2. two 18-bit multipliers
// 3. one 36-bit multipliers
// Coder : Xifan Tang
//-----------------------------------------------------
module mult_36x36 (
input [0:35] a,
input [0:35] b,
output [0:71] out,
input [0:1] mode);
reg [0:71] out_reg;
always @(mode, a, b) begin
if (2'b01 == mode) begin
out_reg[0:17] <= a[0:8] * b[0:8];
out_reg[18:35] <= a[9:17] * b[9:17];
out_reg[36:53] <= a[18:26] * b[18:26];
out_reg[54:71] <= a[27:35] * b[27:35];
end else if (2'b10 == mode) begin
out_reg[0:35] <= a[0:17] * b[0:17];
out_reg[36:71] <= a[18:35] * b[18:35];
end else begin
out_reg <= a * b;
end
end
assign out = out_reg;
endmodule