Files
vortex/hw/rtl/libs/VX_priority_encoder.v
2021-06-23 01:51:23 -07:00

217 lines
9.1 KiB
Verilog

`include "VX_platform.vh"
module VX_priority_encoder #(
parameter N = 1,
parameter REVERSE = 0,
parameter FAST = 1,
parameter LN = `LOG2UP(N)
) (
input wire [N-1:0] data_in,
output wire [N-1:0] onehot,
output wire [LN-1:0] index,
output wire valid_out
);
if (N == 1) begin
assign onehot = data_in;
assign index = 0;
assign valid_out = data_in;
end else if (N == 2) begin
assign onehot = {~data_in[REVERSE], data_in[REVERSE]};
assign index = ~data_in[REVERSE];
assign valid_out = (| data_in);
end else if (N == 4) begin
reg [LN-1:0] index_r;
reg [N-1:0] onehot_r;
if (REVERSE) begin
always @(*) begin
casez (data_in)
4'b1???: begin onehot_r = 4'b0001; index_r = LN'(0); end
4'b01??: begin onehot_r = 4'b0010; index_r = LN'(1); end
4'b001?: begin onehot_r = 4'b0100; index_r = LN'(2); end
4'b0001: begin onehot_r = 4'b1000; index_r = LN'(3); end
default: begin onehot_r = 'x; index_r = 'x; end
endcase
end
end else begin
always @(*) begin
casez (data_in)
4'b???1: begin onehot_r = 4'b0001; index_r = LN'(0); end
4'b??10: begin onehot_r = 4'b0010; index_r = LN'(1); end
4'b?100: begin onehot_r = 4'b0100; index_r = LN'(2); end
4'b1000: begin onehot_r = 4'b1000; index_r = LN'(3); end
default: begin onehot_r = 'x; index_r = 'x; end
endcase
end
end
assign index = index_r;
assign onehot = onehot_r;
end else if (N == 8) begin
reg [LN-1:0] index_r;
reg [N-1:0] onehot_r;
if (REVERSE) begin
always @(*) begin
casez (data_in)
8'b1???????: begin onehot_r = 8'b00000001; index_r = LN'(0); end
8'b01??????: begin onehot_r = 8'b00000010; index_r = LN'(1); end
8'b001?????: begin onehot_r = 8'b00000100; index_r = LN'(2); end
8'b0001????: begin onehot_r = 8'b00001000; index_r = LN'(3); end
8'b00001???: begin onehot_r = 8'b00010000; index_r = LN'(4); end
8'b000001??: begin onehot_r = 8'b00100000; index_r = LN'(5); end
8'b0000001?: begin onehot_r = 8'b01000000; index_r = LN'(6); end
8'b00000001: begin onehot_r = 8'b10000000; index_r = LN'(7); end
default: begin onehot_r = 'x; index_r = 'x; end
endcase
end
end else begin
always @(*) begin
casez (data_in)
8'b???????1: begin onehot_r = 8'b00000001; index_r = LN'(0); end
8'b??????10: begin onehot_r = 8'b00000010; index_r = LN'(1); end
8'b?????100: begin onehot_r = 8'b00000100; index_r = LN'(2); end
8'b????1000: begin onehot_r = 8'b00001000; index_r = LN'(3); end
8'b???10000: begin onehot_r = 8'b00010000; index_r = LN'(4); end
8'b??100000: begin onehot_r = 8'b00100000; index_r = LN'(5); end
8'b?1000000: begin onehot_r = 8'b01000000; index_r = LN'(6); end
8'b10000000: begin onehot_r = 8'b10000000; index_r = LN'(7); end
default: begin onehot_r = 'x; index_r = 'x; end
endcase
end
end
assign index = index_r;
assign onehot = onehot_r;
end else if (N == 16) begin
reg [LN-1:0] index_r;
reg [N-1:0] onehot_r;
if (REVERSE) begin
always @(*) begin
casez (data_in)
16'b1???????????????: begin onehot_r = 16'b0000000000000001; index_r = LN'(0); end
16'b01??????????????: begin onehot_r = 16'b0000000000000010; index_r = LN'(1); end
16'b001?????????????: begin onehot_r = 16'b0000000000000100; index_r = LN'(2); end
16'b0001????????????: begin onehot_r = 16'b0000000000001000; index_r = LN'(3); end
16'b00001???????????: begin onehot_r = 16'b0000000000010000; index_r = LN'(4); end
16'b000001??????????: begin onehot_r = 16'b0000000000100000; index_r = LN'(5); end
16'b0000001?????????: begin onehot_r = 16'b0000000001000000; index_r = LN'(6); end
16'b00000001????????: begin onehot_r = 16'b0000000010000000; index_r = LN'(7); end
16'b000000001???????: begin onehot_r = 16'b0000000100000000; index_r = LN'(8); end
16'b0000000001??????: begin onehot_r = 16'b0000001000000000; index_r = LN'(9); end
16'b00000000001?????: begin onehot_r = 16'b0000010000000000; index_r = LN'(10); end
16'b000000000001????: begin onehot_r = 16'b0000100000000000; index_r = LN'(11); end
16'b0000000000001???: begin onehot_r = 16'b0001000000000000; index_r = LN'(12); end
16'b00000000000001??: begin onehot_r = 16'b0010000000000000; index_r = LN'(13); end
16'b000000000000001?: begin onehot_r = 16'b0100000000000000; index_r = LN'(14); end
16'b0000000000000001: begin onehot_r = 16'b1000000000000000; index_r = LN'(15); end
default: begin onehot_r = 'x; index_r = 'x; end
endcase
end
end else begin
always @(*) begin
casez (data_in)
16'b???????????????1: begin onehot_r = 16'b0000000000000001; index_r = LN'(0); end
16'b??????????????10: begin onehot_r = 16'b0000000000000010; index_r = LN'(1); end
16'b?????????????100: begin onehot_r = 16'b0000000000000100; index_r = LN'(2); end
16'b????????????1000: begin onehot_r = 16'b0000000000001000; index_r = LN'(3); end
16'b???????????10000: begin onehot_r = 16'b0000000000010000; index_r = LN'(4); end
16'b??????????100000: begin onehot_r = 16'b0000000000100000; index_r = LN'(5); end
16'b?????????1000000: begin onehot_r = 16'b0000000001000000; index_r = LN'(6); end
16'b????????10000000: begin onehot_r = 16'b0000000010000000; index_r = LN'(7); end
16'b???????100000000: begin onehot_r = 16'b0000000100000000; index_r = LN'(8); end
16'b??????1000000000: begin onehot_r = 16'b0000001000000000; index_r = LN'(9); end
16'b?????10000000000: begin onehot_r = 16'b0000010000000000; index_r = LN'(10); end
16'b????100000000000: begin onehot_r = 16'b0000100000000000; index_r = LN'(11); end
16'b???1000000000000: begin onehot_r = 16'b0001000000000000; index_r = LN'(12); end
16'b??10000000000000: begin onehot_r = 16'b0010000000000000; index_r = LN'(13); end
16'b?100000000000000: begin onehot_r = 16'b0100000000000000; index_r = LN'(14); end
16'b1000000000000000: begin onehot_r = 16'b1000000000000000; index_r = LN'(15); end
default: begin onehot_r = 'x; index_r = 'x; end
endcase
end
end
assign index = index_r;
assign onehot = onehot_r;
end else if (FAST) begin
wire [N-1:0] scan_lo;
VX_scan #(
.N (N),
.OP (2),
.REVERSE (REVERSE)
) scan (
.data_in (data_in),
.data_out (scan_lo)
);
if (REVERSE) begin
assign onehot = scan_lo & {1'b1, (~scan_lo[N-1:1])};
assign valid_out = scan_lo[0];
end else begin
assign onehot = scan_lo & {(~scan_lo[N-2:0]), 1'b1};
assign valid_out = scan_lo[N-1];
end
VX_onehot_encoder #(
.N (N),
.REVERSE (REVERSE)
) onehot_encoder (
.data_in (onehot),
.data_out (index),
`UNUSED_PIN (valid)
);
end else begin
reg [LN-1:0] index_r;
reg [N-1:0] onehot_r;
if (REVERSE) begin
always @(*) begin
index_r = 'x;
onehot_r = 'x;
for (integer i = 0; i < N; ++i) begin
if (data_in[i]) begin
index_r = LN'(i);
onehot_r = 0;
onehot_r[i] = 1'b1;
end
end
end
end else begin
always @(*) begin
index_r = 'x;
onehot_r = 'x;
for (integer i = N-1; i >= 0; --i) begin
if (data_in[i]) begin
index_r = LN'(i);
onehot_r = 0;
onehot_r[i] = 1'b1;
end
end
end
end
assign index = index_r;
assign onehot = onehot_r;
end
assign valid_out = (| data_in);
endmodule