vortex/hw/rtl/libs/VX_serial_div.sv

101 lines
3.4 KiB
Systemverilog

// Copyright © 2019-2023
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
`include "VX_platform.vh"
`TRACING_OFF
module VX_serial_div #(
parameter WIDTHN = 32,
parameter WIDTHD = 32,
parameter WIDTHQ = 32,
parameter WIDTHR = 32,
parameter LANES = 1
) (
input wire clk,
input wire reset,
input wire strobe,
output wire busy,
input wire is_signed,
input wire [LANES-1:0][WIDTHN-1:0] numer,
input wire [LANES-1:0][WIDTHD-1:0] denom,
output wire [LANES-1:0][WIDTHQ-1:0] quotient,
output wire [LANES-1:0][WIDTHR-1:0] remainder
);
localparam MIN_ND = (WIDTHN < WIDTHD) ? WIDTHN : WIDTHD;
localparam CNTRW = `CLOG2(WIDTHN);
reg [LANES-1:0][WIDTHN + MIN_ND:0] working;
reg [LANES-1:0][WIDTHD-1:0] denom_r;
wire [LANES-1:0][WIDTHN-1:0] numer_qual;
wire [LANES-1:0][WIDTHD-1:0] denom_qual;
wire [LANES-1:0][WIDTHD:0] sub_result;
reg [LANES-1:0] inv_quot, inv_rem;
reg [CNTRW-1:0] cntr;
reg busy_r;
for (genvar i = 0; i < LANES; ++i) begin : g_setup
wire negate_numer = is_signed && numer[i][WIDTHN-1];
wire negate_denom = is_signed && denom[i][WIDTHD-1];
assign numer_qual[i] = negate_numer ? -$signed(numer[i]) : numer[i];
assign denom_qual[i] = negate_denom ? -$signed(denom[i]) : denom[i];
assign sub_result[i] = working[i][WIDTHN + MIN_ND : WIDTHN] - denom_r[i];
end
always @(posedge clk) begin
if (reset) begin
busy_r <= 0;
end else begin
if (strobe) begin
busy_r <= 1;
end
if (busy && cntr == 0) begin
busy_r <= 0;
end
end
cntr <= cntr - CNTRW'(1);
if (strobe) begin
cntr <= CNTRW'(WIDTHN-1);
end
end
for (genvar i = 0; i < LANES; ++i) begin : g_div
always @(posedge clk) begin
if (strobe) begin
working[i] <= {{WIDTHD{1'b0}}, numer_qual[i], 1'b0};
denom_r[i] <= denom_qual[i];
inv_quot[i] <= (denom[i] != 0) && is_signed && (numer[i][31] ^ denom[i][31]);
inv_rem[i] <= is_signed && numer[i][31];
end else if (busy_r) begin
working[i] <= sub_result[i][WIDTHD] ? {working[i][WIDTHN+MIN_ND-1:0], 1'b0} :
{sub_result[i][WIDTHD-1:0], working[i][WIDTHN-1:0], 1'b1};
end
end
end
for (genvar i = 0; i < LANES; ++i) begin : g_output
wire [WIDTHQ-1:0] q = working[i][WIDTHQ-1:0];
wire [WIDTHR-1:0] r = working[i][WIDTHN+WIDTHR:WIDTHN+1];
assign quotient[i] = inv_quot[i] ? -$signed(q) : q;
assign remainder[i] = inv_rem[i] ? -$signed(r) : r;
end
assign busy = busy_r;
endmodule
`TRACING_ON