Files
kernels/hw/rtl/libs/VX_divide.v
2020-06-28 14:39:18 -07:00

108 lines
3.2 KiB
Verilog

`include "VX_define.vh"
module VX_divide #(
parameter WIDTHN = 1,
parameter WIDTHD = 1,
parameter NSIGNED = 0,
parameter DSIGNED = 0,
parameter PIPELINE = 0
) (
input wire clk,
input wire reset,
input [WIDTHN-1:0] numer,
input [WIDTHD-1:0] denom,
output reg [WIDTHN-1:0] quotient,
output reg [WIDTHD-1:0] remainder
);
`ifdef QUARTUS
lpm_divide quartus_div (
.clock (clk),
.numer (numer),
.denom (denom),
.quotient (quotient),
.remain (remainder),
.aclr (1'b0),
.clken (1'b1)
);
defparam
quartus_div.lpm_type = "LPM_DIVIDE",
quartus_div.lpm_widthn = WIDTHN,
quartus_div.lpm_widthd = WIDTHD,
quartus_div.lpm_nrepresentation = NSIGNED ? "SIGNED" : "UNSIGNED",
quartus_div.lpm_drepresentation = DSIGNED ? "SIGNED" : "UNSIGNED",
quartus_div.lpm_hint = "LPM_REMAINDERPOSITIVE=FALSE,MAXIMIZE_SPEED=9",
quartus_div.lpm_pipeline = PIPELINE;
`else
reg [WIDTHN-1:0] quotient_unqual;
reg [WIDTHD-1:0] remainder_unqual;
always @(*) begin
`ifndef SYNTHESIS
// this edge case kills verilator in some cases by causing a division
// overflow exception. INT_MIN / -1 (on x86)
if (numer == {1'b1, (WIDTHN-1)'(0)}
&& denom == {WIDTHD{1'b1}}) begin
quotient_unqual = 0;
remainder_unqual = 0;
end else
`endif
begin
if (NSIGNED && DSIGNED) begin
quotient_unqual = $signed(numer) / $signed(denom);
remainder_unqual = $signed(numer) % $signed(denom);
end
else if (NSIGNED && !DSIGNED) begin
quotient_unqual = $signed(numer) / denom;
remainder_unqual = $signed(numer) % denom;
end
else if (!NSIGNED && DSIGNED) begin
quotient_unqual = numer / $signed(denom);
remainder_unqual = numer % $signed(denom);
end
else begin
quotient_unqual = numer / denom;
remainder_unqual = numer % denom;
end
end
end
if (PIPELINE == 0) begin
assign quotient = quotient_unqual;
assign remainder = remainder_unqual;
end else begin
reg [WIDTHN-1:0] quotient_pipe [0:PIPELINE-1];
reg [WIDTHD-1:0] remainder_pipe [0:PIPELINE-1];
genvar i;
for (i = 0; i < PIPELINE; i++) begin
always @(posedge clk) begin
if (reset) begin
quotient_pipe[i] <= 0;
remainder_pipe[i] <= 0;
end
else begin
if (i == 0) begin
quotient_pipe[0] <= quotient_unqual;
remainder_pipe[0] <= remainder_unqual;
end else begin
quotient_pipe[i] <= quotient_pipe[i-1];
remainder_pipe[i] <= remainder_pipe[i-1];
end
end
end
end
assign quotient = quotient_pipe[PIPELINE-1];
assign remainder = remainder_pipe[PIPELINE-1];
end
`endif
endmodule