yosys/techlibs/quicklogic/qlf_k6n10f/ufifo_ctl.v

621 lines
19 KiB
Verilog

// Copyright 2020-2022 F4PGA Authors
//
// 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.
//
// SPDX-License-Identifier: Apache-2.0
`default_nettype wire
module fifo_ctl (
raddr,
waddr,
fflags,
ren_o,
sync,
rmode,
wmode,
rclk,
rst_R_n,
wclk,
rst_W_n,
ren,
wen,
upaf,
upae
);
parameter ADDR_WIDTH = 11;
parameter FIFO_WIDTH = 3'd2;
parameter DEPTH = 6;
output wire [ADDR_WIDTH - 1:0] raddr;
output wire [ADDR_WIDTH - 1:0] waddr;
output wire [7:0] fflags;
output wire ren_o;
input wire sync;
input wire [1:0] rmode;
input wire [1:0] wmode;
(* clkbuf_sink *)
input wire rclk;
input wire rst_R_n;
(* clkbuf_sink *)
input wire wclk;
input wire rst_W_n;
input wire ren;
input wire wen;
input wire [ADDR_WIDTH - 1:0] upaf;
input wire [ADDR_WIDTH - 1:0] upae;
localparam ADDR_PLUS_ONE = ADDR_WIDTH + 1;
reg [ADDR_WIDTH:0] pushtopop1;
reg [ADDR_WIDTH:0] pushtopop2;
reg [ADDR_WIDTH:0] poptopush1;
reg [ADDR_WIDTH:0] poptopush2;
wire [ADDR_WIDTH:0] pushtopop0;
wire [ADDR_WIDTH:0] poptopush0;
wire [ADDR_WIDTH:0] smux_poptopush;
wire [ADDR_WIDTH:0] smux_pushtopop;
assign smux_poptopush = (sync ? poptopush0 : poptopush2);
assign smux_pushtopop = (sync ? pushtopop0 : pushtopop2);
always @(posedge rclk or negedge rst_R_n)
if (~rst_R_n) begin
pushtopop1 <= 'h0;
pushtopop2 <= 'h0;
end
else begin
pushtopop1 = pushtopop0;
pushtopop2 = pushtopop1;
end
always @(posedge wclk or negedge rst_W_n)
if (~rst_W_n) begin
poptopush1 <= 'h0;
poptopush2 <= 'h0;
end
else begin
poptopush1 <= poptopush0;
poptopush2 <= poptopush1;
end
fifo_push #(
.ADDR_WIDTH(ADDR_WIDTH),
.DEPTH(DEPTH)
) u_fifo_push(
.wclk(wclk),
.wen(wen),
.rst_n(rst_W_n),
.rmode(rmode),
.wmode(wmode),
.gcout(pushtopop0),
.gcin(smux_poptopush),
.ff_waddr(waddr),
.pushflags(fflags[7:4]),
.upaf(upaf)
);
fifo_pop #(
.ADDR_WIDTH(ADDR_WIDTH),
.FIFO_WIDTH(FIFO_WIDTH),
.DEPTH(DEPTH)
) u_fifo_pop(
.rclk(rclk),
.ren_in(ren),
.rst_n(rst_R_n),
.rmode(rmode),
.wmode(wmode),
.ren_o(ren_o),
.gcout(poptopush0),
.gcin(smux_pushtopop),
.out_raddr(raddr),
.popflags(fflags[3:0]),
.upae(upae)
);
endmodule
module fifo_push (
pushflags,
gcout,
ff_waddr,
rst_n,
wclk,
wen,
rmode,
wmode,
gcin,
upaf
);
parameter ADDR_WIDTH = 11;
parameter DEPTH = 6;
output wire [3:0] pushflags;
output wire [ADDR_WIDTH:0] gcout;
output wire [ADDR_WIDTH - 1:0] ff_waddr;
input rst_n;
(* clkbuf_sink *)
input wclk;
input wen;
input [1:0] rmode;
input [1:0] wmode;
input [ADDR_WIDTH:0] gcin;
input [ADDR_WIDTH - 1:0] upaf;
localparam ADDR_PLUS_ONE = ADDR_WIDTH + 1;
reg full_next;
reg full;
reg paf_next;
reg paf;
reg fmo;
reg fmo_next;
reg overflow;
reg p1;
reg p2;
reg f1;
reg f2;
reg q1;
reg q2;
reg [1:0] gmode;
reg [ADDR_WIDTH:0] waddr;
reg [ADDR_WIDTH:0] raddr;
reg [ADDR_WIDTH:0] gcout_reg;
reg [ADDR_WIDTH:0] gcout_next;
reg [ADDR_WIDTH:0] raddr_next;
reg [ADDR_WIDTH - 1:0] paf_thresh;
wire overflow_next;
wire [ADDR_WIDTH:0] waddr_next;
wire [ADDR_WIDTH:0] gc8out_next;
wire [ADDR_WIDTH - 1:0] gc16out_next;
wire [ADDR_WIDTH - 2:0] gc32out_next;
wire [ADDR_WIDTH:0] tmp;
wire [ADDR_WIDTH:0] next_count;
wire [ADDR_WIDTH:0] count;
wire [ADDR_WIDTH:0] fbytes;
genvar i;
assign next_count = fbytes - (waddr_next >= raddr_next ? waddr_next - raddr_next : (~raddr_next + waddr_next) + 1);
assign count = fbytes - (waddr >= raddr ? waddr - raddr : (~raddr + waddr) + 1);
assign fbytes = 1 << (DEPTH + 5);
always @(*) begin
paf_thresh = wmode[1] ? upaf : (wmode[0] ? upaf << 1 : upaf << 2);
end
always @(*)
case (wmode)
2'h0, 2'h1, 2'h2: begin
full_next = (wen ? f1 : f2);
fmo_next = (wen ? p1 : p2);
paf_next = (wen ? q1 : q2);
end
default: begin
full_next = 1'b0;
fmo_next = 1'b0;
paf_next = 1'b0;
end
endcase
always @(*) begin : PUSH_FULL_FLAGS
f1 = 1'b0;
f2 = 1'b0;
p1 = 1'b0;
p2 = 1'b0;
q1 = next_count < {1'b0, paf_thresh};
q2 = count < {1'b0, paf_thresh};
case (wmode)
2'h0:
case (DEPTH)
3'h6: begin
f1 = {~waddr_next[11], waddr_next[10:2]} == raddr_next[11:2];
f2 = {~waddr[11], waddr[10:2]} == raddr_next[11:2];
p1 = ((waddr_next[10:2] + 1) & 9'h1ff) == raddr_next[10:2];
p2 = ((waddr[10:2] + 1) & 9'h1ff) == raddr_next[10:2];
end
3'h5: begin
f1 = {~waddr_next[10], waddr_next[9:2]} == raddr_next[10:2];
f2 = {~waddr[10], waddr[9:2]} == raddr_next[10:2];
p1 = ((waddr_next[9:2] + 1) & 8'hff) == raddr_next[9:2];
p2 = ((waddr[9:2] + 1) & 8'hff) == raddr_next[9:2];
end
3'h4: begin
f1 = {~waddr_next[9], waddr_next[8:2]} == raddr_next[9:2];
f2 = {~waddr[9], waddr[8:2]} == raddr_next[9:2];
p1 = ((waddr_next[8:2] + 1) & 7'h7f) == raddr_next[8:2];
p2 = ((waddr[8:2] + 1) & 7'h7f) == raddr_next[8:2];
end
3'h3: begin
f1 = {~waddr_next[8], waddr_next[7:2]} == raddr_next[8:2];
f2 = {~waddr[8], waddr[7:2]} == raddr_next[8:2];
p1 = ((waddr_next[7:2] + 1) & 6'h3f) == raddr_next[7:2];
p2 = ((waddr[7:2] + 1) & 6'h3f) == raddr_next[7:2];
end
3'h2: begin
f1 = {~waddr_next[7], waddr_next[6:2]} == raddr_next[7:2];
f2 = {~waddr[7], waddr[6:2]} == raddr_next[7:2];
p1 = ((waddr_next[6:2] + 1) & 5'h1f) == raddr_next[6:2];
p2 = ((waddr[6:2] + 1) & 5'h1f) == raddr_next[6:2];
end
3'h1: begin
f1 = {~waddr_next[6], waddr_next[5:2]} == raddr_next[6:2];
f2 = {~waddr[6], waddr[5:2]} == raddr_next[6:2];
p1 = ((waddr_next[5:2] + 1) & 4'hf) == raddr_next[5:2];
p2 = ((waddr[5:2] + 1) & 4'hf) == raddr_next[5:2];
end
3'h0: begin
f1 = {~waddr_next[5], waddr_next[4:2]} == raddr_next[5:2];
f2 = {~waddr[5], waddr[4:2]} == raddr_next[5:2];
p1 = ((waddr_next[4:2] + 1) & 3'h7) == raddr_next[4:2];
p2 = ((waddr[4:2] + 1) & 3'h7) == raddr_next[4:2];
end
3'h7: begin
f1 = {~waddr_next[ADDR_WIDTH], waddr_next[ADDR_WIDTH - 1:2]} == raddr_next[ADDR_WIDTH:2];
f2 = {~waddr[ADDR_WIDTH], waddr[ADDR_WIDTH - 1:2]} == raddr_next[ADDR_WIDTH:2];
p1 = ((waddr_next[ADDR_WIDTH - 1:2] + 1) & {ADDR_WIDTH - 2 {1'b1}}) == raddr_next[ADDR_WIDTH - 1:2];
p2 = ((waddr[ADDR_WIDTH - 1:2] + 1) & {ADDR_WIDTH - 2 {1'b1}}) == raddr_next[ADDR_WIDTH - 1:2];
end
endcase
2'h1:
case (DEPTH)
3'h6: begin
f1 = {~waddr_next[11], waddr_next[10:1]} == raddr_next[11:1];
f2 = {~waddr[11], waddr[10:1]} == raddr_next[11:1];
p1 = ((waddr_next[10:1] + 1) & 10'h3ff) == raddr_next[10:1];
p2 = ((waddr[10:1] + 1) & 10'h3ff) == raddr_next[10:1];
end
3'h5: begin
f1 = {~waddr_next[10], waddr_next[9:1]} == raddr_next[10:1];
f2 = {~waddr[10], waddr[9:1]} == raddr_next[10:1];
p1 = ((waddr_next[9:1] + 1) & 9'h1ff) == raddr_next[9:1];
p2 = ((waddr[9:1] + 1) & 9'h1ff) == raddr_next[9:1];
end
3'h4: begin
f1 = {~waddr_next[9], waddr_next[8:1]} == raddr_next[9:1];
f2 = {~waddr[9], waddr[8:1]} == raddr_next[9:1];
p1 = ((waddr_next[8:1] + 1) & 8'hff) == raddr_next[8:1];
p2 = ((waddr[8:1] + 1) & 8'hff) == raddr_next[8:1];
end
3'h3: begin
f1 = {~waddr_next[8], waddr_next[7:1]} == raddr_next[8:1];
f2 = {~waddr[8], waddr[7:1]} == raddr_next[8:1];
p1 = ((waddr_next[7:1] + 1) & 7'h7f) == raddr_next[7:1];
p2 = ((waddr[7:1] + 1) & 7'h7f) == raddr_next[7:1];
end
3'h2: begin
f1 = {~waddr_next[7], waddr_next[6:1]} == raddr_next[7:1];
f2 = {~waddr[7], waddr[6:1]} == raddr_next[7:1];
p1 = ((waddr_next[6:1] + 1) & 6'h3f) == raddr_next[6:1];
p2 = ((waddr[6:1] + 1) & 6'h3f) == raddr_next[6:1];
end
3'h1: begin
f1 = {~waddr_next[6], waddr_next[5:1]} == raddr_next[6:1];
f2 = {~waddr[6], waddr[5:1]} == raddr_next[6:1];
p1 = ((waddr_next[5:1] + 1) & 5'h1f) == raddr_next[5:1];
p2 = ((waddr[5:1] + 1) & 5'h1f) == raddr_next[5:1];
end
3'h0: begin
f1 = {~waddr_next[5], waddr_next[4:1]} == raddr_next[5:1];
f2 = {~waddr[5], waddr[4:1]} == raddr_next[5:1];
p1 = ((waddr_next[4:1] + 1) & 4'hf) == raddr_next[4:1];
p2 = ((waddr[4:1] + 1) & 4'hf) == raddr_next[4:1];
end
3'h7: begin
f1 = {~waddr_next[ADDR_WIDTH], waddr_next[ADDR_WIDTH - 1:1]} == raddr_next[ADDR_WIDTH:1];
f2 = {~waddr[ADDR_WIDTH], waddr[ADDR_WIDTH - 1:1]} == raddr_next[ADDR_WIDTH:1];
p1 = ((waddr_next[ADDR_WIDTH - 1:1] + 1) & {ADDR_WIDTH - 1 {1'b1}}) == raddr_next[ADDR_WIDTH - 1:1];
p2 = ((waddr[ADDR_WIDTH - 1:1] + 1) & {ADDR_WIDTH - 1 {1'b1}}) == raddr_next[ADDR_WIDTH - 1:1];
end
endcase
2'h2:
case (DEPTH)
3'h6: begin
f1 = {~waddr_next[11], waddr_next[10:0]} == raddr_next[11:0];
f2 = {~waddr[11], waddr[10:0]} == raddr_next[11:0];
p1 = ((waddr_next[10:0] + 1) & 11'h7ff) == raddr_next[10:0];
p2 = ((waddr[10:0] + 1) & 11'h7ff) == raddr_next[10:0];
end
3'h5: begin
f1 = {~waddr_next[10], waddr_next[9:0]} == raddr_next[10:0];
f2 = {~waddr[10], waddr[9:0]} == raddr_next[10:0];
p1 = ((waddr_next[9:0] + 1) & 10'h3ff) == raddr_next[9:0];
p2 = ((waddr[9:0] + 1) & 10'h3ff) == raddr_next[9:0];
end
3'h4: begin
f1 = {~waddr_next[9], waddr_next[8:0]} == raddr_next[9:0];
f2 = {~waddr[9], waddr[8:0]} == raddr_next[9:0];
p1 = ((waddr_next[8:0] + 1) & 9'h1ff) == raddr_next[8:0];
p2 = ((waddr[8:0] + 1) & 9'h1ff) == raddr_next[8:0];
end
3'h3: begin
f1 = {~waddr_next[8], waddr_next[7:0]} == raddr_next[8:0];
f2 = {~waddr[8], waddr[7:0]} == raddr_next[8:0];
p1 = ((waddr_next[7:0] + 1) & 8'hff) == raddr_next[7:0];
p2 = ((waddr[7:0] + 1) & 8'hff) == raddr_next[7:0];
end
3'h2: begin
f1 = {~waddr_next[7], waddr_next[6:0]} == raddr_next[7:0];
f2 = {~waddr[7], waddr[6:0]} == raddr_next[7:0];
p1 = ((waddr_next[6:0] + 1) & 7'h7f) == raddr_next[6:0];
p2 = ((waddr[6:0] + 1) & 7'h7f) == raddr_next[6:0];
end
3'h1: begin
f1 = {~waddr_next[6], waddr_next[5:0]} == raddr_next[6:0];
f2 = {~waddr[6], waddr[5:0]} == raddr_next[6:0];
p1 = ((waddr_next[5:0] + 1) & 6'h3f) == raddr_next[5:0];
p2 = ((waddr[5:0] + 1) & 6'h3f) == raddr_next[5:0];
end
3'h0: begin
f1 = {~waddr_next[5], waddr_next[4:0]} == raddr_next[5:0];
f2 = {~waddr[5], waddr[4:0]} == raddr_next[5:0];
p1 = ((waddr_next[4:0] + 1) & 5'h1f) == raddr_next[4:0];
p2 = ((waddr[4:0] + 1) & 5'h1f) == raddr_next[4:0];
end
3'h7: begin
f1 = {~waddr_next[ADDR_WIDTH], waddr_next[ADDR_WIDTH - 1:0]} == raddr_next[ADDR_WIDTH:0];
f2 = {~waddr[ADDR_WIDTH], waddr[ADDR_WIDTH - 1:0]} == raddr_next[ADDR_WIDTH:0];
p1 = ((waddr_next[ADDR_WIDTH - 1:0] + 1) & {ADDR_WIDTH {1'b1}}) == raddr_next[ADDR_WIDTH - 1:0];
p2 = ((waddr[ADDR_WIDTH - 1:0] + 1) & {ADDR_WIDTH {1'b1}}) == raddr_next[ADDR_WIDTH - 1:0];
end
endcase
2'h3: begin
f1 = 1'b0;
f2 = 1'b0;
p1 = 1'b0;
p2 = 1'b0;
end
endcase
end
always @(*)
case (wmode)
2'h0: gmode = 2'h0;
2'h1: gmode = (rmode == 2'h0 ? 2'h0 : 2'h1);
2'h2: gmode = (rmode == 2'h2 ? 2'h2 : rmode);
2'h3: gmode = 2'h3;
endcase
assign gc8out_next = (waddr_next >> 1) ^ waddr_next;
assign gc16out_next = (waddr_next >> 2) ^ (waddr_next >> 1);
assign gc32out_next = (waddr_next >> 3) ^ (waddr_next >> 2);
always @(*)
if (wen)
case (gmode)
2'h2: gcout_next = gc8out_next;
2'h1: gcout_next = {1'b0, gc16out_next};
2'h0: gcout_next = {2'b00, gc32out_next};
default: gcout_next = {ADDR_PLUS_ONE {1'b0}};
endcase
else
gcout_next = {ADDR_PLUS_ONE {1'b0}};
always @(posedge wclk or negedge rst_n)
if (~rst_n) begin
full <= 1'b0;
fmo <= 1'b0;
paf <= 1'b0;
raddr <= {ADDR_PLUS_ONE {1'b0}};
end
else begin
full <= full_next;
fmo <= fmo_next;
paf <= paf_next;
case (gmode)
0: raddr <= raddr_next & {{ADDR_WIDTH - 1 {1'b1}}, 2'b00};
1: raddr <= raddr_next & {{ADDR_WIDTH {1'b1}}, 1'b0};
2: raddr <= raddr_next & {ADDR_WIDTH + 1 {1'b1}};
3: raddr <= 12'h000;
endcase
end
assign overflow_next = full & wen;
always @(posedge wclk or negedge rst_n)
if (~rst_n)
overflow <= 1'b0;
else if (wen == 1'b1)
overflow <= overflow_next;
always @(posedge wclk or negedge rst_n)
if (~rst_n) begin
waddr <= {ADDR_WIDTH + 1 {1'b0}};
gcout_reg <= {ADDR_WIDTH + 1 {1'b0}};
end
else if (wen == 1'b1) begin
waddr <= waddr_next;
gcout_reg <= gcout_next;
end
assign gcout = gcout_reg;
generate
for (i = 0; i < (ADDR_WIDTH + 1); i = i + 1) begin : genblk1
assign tmp[i] = ^(gcin >> i);
end
endgenerate
always @(*)
case (gmode)
2'h0: raddr_next = {tmp[ADDR_WIDTH - 2:0], 2'b00} & {{ADDR_WIDTH - 1 {1'b1}}, 2'b00};
2'h1: raddr_next = {tmp[ADDR_WIDTH - 1:0], 1'b0} & {{ADDR_WIDTH {1'b1}}, 1'b0};
2'h2: raddr_next = {tmp[ADDR_WIDTH:0]} & {ADDR_WIDTH + 1 {1'b1}};
default: raddr_next = {ADDR_WIDTH + 1 {1'b0}};
endcase
assign ff_waddr = waddr[ADDR_WIDTH - 1:0];
assign pushflags = {full, fmo, paf, overflow};
assign waddr_next = waddr + (wmode == 2'h0 ? 'h4 : (wmode == 2'h1 ? 'h2 : 'h1));
endmodule
module fifo_pop (
ren_o,
popflags,
out_raddr,
gcout,
rst_n,
rclk,
ren_in,
rmode,
wmode,
gcin,
upae
);
parameter ADDR_WIDTH = 11;
parameter FIFO_WIDTH = 3'd2;
parameter DEPTH = 6;
output wire ren_o;
output wire [3:0] popflags;
output reg [ADDR_WIDTH - 1:0] out_raddr;
output wire [ADDR_WIDTH:0] gcout;
input rst_n;
(* clkbuf_sink *)
input rclk;
input ren_in;
input [1:0] rmode;
input [1:0] wmode;
input [ADDR_WIDTH:0] gcin;
input [ADDR_WIDTH - 1:0] upae;
localparam ADDR_PLUS_ONE = ADDR_WIDTH + 1;
reg empty;
reg epo;
reg pae;
reg underflow;
reg e1;
reg e2;
reg o1;
reg o2;
reg q1;
reg q2;
reg [1:0] bwl_sel;
reg [1:0] gmode;
reg [ADDR_WIDTH - 1:0] ff_raddr;
reg [ADDR_WIDTH:0] waddr;
reg [ADDR_WIDTH:0] raddr;
reg [ADDR_WIDTH:0] gcout_reg;
reg [ADDR_WIDTH:0] gcout_next;
reg [ADDR_WIDTH:0] waddr_next;
reg [ADDR_WIDTH - 1:0] pae_thresh;
wire ren_out;
wire empty_next;
wire pae_next;
wire epo_next;
wire [ADDR_WIDTH - 2:0] gc32out_next;
wire [ADDR_WIDTH - 1:0] gc16out_next;
wire [ADDR_WIDTH:0] gc8out_next;
wire [ADDR_WIDTH:0] raddr_next;
wire [ADDR_WIDTH - 1:0] ff_raddr_next;
wire [ADDR_WIDTH:0] tmp;
wire [ADDR_PLUS_ONE:0] next_count;
wire [ADDR_PLUS_ONE:0] count;
wire [ADDR_PLUS_ONE:0] fbytes;
genvar i;
assign next_count = waddr - raddr_next;
assign count = waddr - raddr;
assign fbytes = 1 << (DEPTH + 5);
always @(*) pae_thresh = rmode[1] ? upae : (rmode[0] ? upae << 1 : upae << 2);
assign ren_out = (empty ? 1'b1 : ren_in);
always @(*)
case (rmode)
2'h0: gmode = 2'h0;
2'h1: gmode = (wmode == 2'h0 ? 2'h0 : 2'h1);
2'h2: gmode = (wmode == 2'h2 ? 2'h2 : wmode);
2'h3: gmode = 2'h3;
endcase
always @(*) begin
e1 = 1'b0;
e2 = 1'b0;
o1 = 1'b0;
o2 = 1'b0;
q1 = next_count < {1'b0, pae_thresh};
q2 = count < {1'b0, pae_thresh};
case (rmode)
2'h0: begin
e1 = raddr_next[ADDR_WIDTH:2] == waddr_next[ADDR_WIDTH:2];
e2 = raddr[ADDR_WIDTH:2] == waddr_next[ADDR_WIDTH:2];
o1 = (raddr_next[ADDR_WIDTH:2] + 1) == waddr_next[ADDR_WIDTH:2];
o2 = (raddr[ADDR_WIDTH:2] + 1) == waddr_next[ADDR_WIDTH:2];
end
2'h1: begin
e1 = raddr_next[ADDR_WIDTH:1] == waddr_next[ADDR_WIDTH:1];
e2 = raddr[ADDR_WIDTH:1] == waddr_next[ADDR_WIDTH:1];
o1 = (raddr_next[ADDR_WIDTH:1] + 1) == waddr_next[ADDR_WIDTH:1];
o2 = (raddr[ADDR_WIDTH:1] + 1) == waddr_next[ADDR_WIDTH:1];
end
2'h2: begin
e1 = raddr_next[ADDR_WIDTH:0] == waddr_next[ADDR_WIDTH:0];
e2 = raddr[ADDR_WIDTH:0] == waddr_next[ADDR_WIDTH:0];
o1 = (raddr_next[ADDR_WIDTH:0] + 1) == waddr_next[ADDR_WIDTH:0];
o2 = (raddr[ADDR_WIDTH:0] + 1) == waddr_next[11:0];
end
2'h3: begin
e1 = 1'b0;
e2 = 1'b0;
o1 = 1'b0;
o2 = 1'b0;
end
endcase
end
assign empty_next = (ren_in & !empty ? e1 : e2);
assign epo_next = (ren_in & !empty ? o1 : o2);
assign pae_next = (ren_in & !empty ? q1 : q2);
always @(posedge rclk or negedge rst_n)
if (~rst_n) begin
empty <= 1'b1;
pae <= 1'b1;
epo <= 1'b0;
end
else begin
empty <= empty_next;
pae <= pae_next;
epo <= epo_next;
end
assign gc8out_next = (raddr_next >> 1) ^ raddr_next;
assign gc16out_next = (raddr_next >> 2) ^ (raddr_next >> 1);
assign gc32out_next = (raddr_next >> 3) ^ (raddr_next >> 2);
always @(*)
if (ren_in)
case (gmode)
2'h2: gcout_next = gc8out_next;
2'h1: gcout_next = {1'b0, gc16out_next};
2'h0: gcout_next = {2'b00, gc32out_next};
default: gcout_next = 'h0;
endcase
else
gcout_next = 'h0;
always @(posedge rclk or negedge rst_n)
if (~rst_n)
waddr <= 12'h000;
else
waddr <= waddr_next;
always @(posedge rclk or negedge rst_n)
if (~rst_n) begin
underflow <= 1'b0;
bwl_sel <= 2'h0;
gcout_reg <= 12'h000;
end
else if (ren_in) begin
underflow <= empty;
if (!empty) begin
bwl_sel <= raddr_next[1:0];
gcout_reg <= gcout_next;
end
end
generate
for (i = 0; i < (ADDR_WIDTH + 1); i = i + 1) begin : genblk1
assign tmp[i] = ^(gcin >> i);
end
endgenerate
always @(*)
case (gmode)
2'h0: waddr_next = {tmp[ADDR_WIDTH - 2:0], 2'b00} & {{ADDR_WIDTH - 1 {1'b1}}, 2'b00};
2'h1: waddr_next = {tmp[ADDR_WIDTH - 1:0], 1'b0} & {{ADDR_WIDTH {1'b1}}, 1'b0};
2'h2: waddr_next = {tmp[ADDR_WIDTH:0]} & {ADDR_PLUS_ONE {1'b1}};
default: waddr_next = {ADDR_PLUS_ONE {1'b0}};
endcase
assign ff_raddr_next = ff_raddr + (rmode == 2'h0 ? 'h4 : (rmode == 2'h1 ? 'h2 : 'h1));
assign raddr_next = raddr + (rmode == 2'h0 ? 'h4 : (rmode == 2'h1 ? 'h2 : 'h1));
always @(posedge rclk or negedge rst_n)
if (~rst_n)
ff_raddr <= 1'sb0;
else if (empty & ~empty_next)
ff_raddr <= raddr_next[ADDR_WIDTH - 1:0];
else if ((ren_in & !empty) & ~empty_next)
ff_raddr <= ff_raddr_next;
always @(posedge rclk or negedge rst_n)
if (~rst_n)
raddr <= 12'h000;
else if (ren_in & !empty)
raddr <= raddr_next;
always @(*)
case (FIFO_WIDTH)
3'h2: out_raddr = {ff_raddr[ADDR_WIDTH - 1:1], bwl_sel[0]};
3'h4: out_raddr = {ff_raddr[ADDR_WIDTH - 1:2], bwl_sel};
default: out_raddr = ff_raddr[ADDR_WIDTH - 1:0];
endcase
assign ren_o = ren_out;
assign gcout = gcout_reg;
assign popflags = {empty, epo, pae, underflow};
endmodule
`default_nettype none