Files
kernels/hw/rtl/libs/VX_divide.v
2020-08-05 15:53:59 -07:00

116 lines
3.5 KiB
Verilog

`include "VX_platform.vh"
module VX_divide #(
parameter WIDTHN = 1,
parameter WIDTHD = 1,
parameter WIDTHQ = 1,
parameter WIDTHR = 1,
parameter NSIGNED = 0,
parameter DSIGNED = 0,
parameter PIPELINE = 0
) (
input wire clk,
input wire reset,
input wire clk_en,
input wire [WIDTHN-1:0] numer,
input wire [WIDTHD-1:0] denom,
output wire [WIDTHQ-1:0] quotient,
output wire [WIDTHR-1:0] remainder
);
`ifdef QUARTUS
wire [WIDTHN-1:0] quotient_unqual;
wire [WIDTHD-1:0] remainder_unqual;
lpm_divide divide (
.clock (clk),
.numer (numer),
.denom (denom),
.quotient (quotient_unqual),
.remain (remainder_unqual),
.clken (clk_en)
);
defparam
divide.lpm_type = "LPM_DIVIDE",
divide.lpm_widthn = WIDTHN,
divide.lpm_widthd = WIDTHD,
divide.lpm_nrepresentation = NSIGNED ? "SIGNED" : "UNSIGNED",
divide.lpm_drepresentation = DSIGNED ? "SIGNED" : "UNSIGNED",
divide.lpm_hint = "MAXIMIZE_SPEED=6,LPM_REMAINDERPOSITIVE=FALSE",
divide.lpm_pipeline = PIPELINE;
assign quotient = quotient_unqual [WIDTHQ-1:0];
assign remainder = remainder_unqual [WIDTHR-1:0];
`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)'(1'b0)}
&& 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 [WIDTHQ-1:0];
assign remainder = remainder_unqual [WIDTHR-1:0];
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 if (clk_en) begin
if (i == 0) begin
quotient_pipe[i] <= quotient_unqual;
remainder_pipe[i] <= 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][WIDTHQ-1:0];
assign remainder = remainder_pipe[PIPELINE-1][WIDTHR-1:0];
end
`endif
endmodule