Files
vortex/hw/rtl/libs/VX_pipe_register.sv
2021-09-29 04:48:53 -04:00

77 lines
2.1 KiB
Systemverilog

`include "VX_platform.vh"
`TRACING_OFF
module VX_pipe_register #(
parameter DATAW = 1,
parameter RESETW = DATAW,
parameter DEPTH = 1
) (
input wire clk,
input wire reset,
input wire enable,
input wire [DATAW-1:0] data_in,
output wire [DATAW-1:0] data_out
);
if (DEPTH == 0) begin
`UNUSED_VAR (clk)
`UNUSED_VAR (reset)
`UNUSED_VAR (enable)
assign data_out = data_in;
end else if (DEPTH == 1) begin
if (RESETW == 0) begin
`UNUSED_VAR (reset)
reg [DATAW-1:0] value;
always @(posedge clk) begin
if (enable) begin
value <= data_in;
end
end
assign data_out = value;
end else if (RESETW == DATAW) begin
reg [DATAW-1:0] value;
always @(posedge clk) begin
if (reset) begin
value <= RESETW'(0);
end else if (enable) begin
value <= data_in;
end
end
assign data_out = value;
end else begin
reg [DATAW-RESETW-1:0] value_d;
reg [RESETW-1:0] value_r;
always @(posedge clk) begin
if (reset) begin
value_r <= RESETW'(0);
end else if (enable) begin
value_r <= data_in[DATAW-1:DATAW-RESETW];
end
end
always @(posedge clk) begin
if (enable) begin
value_d <= data_in[DATAW-RESETW-1:0];
end
end
assign data_out = {value_r, value_d};
end
end else begin
VX_shift_register #(
.DATAW (DATAW),
.RESETW (RESETW),
.DEPTH (DEPTH)
) shift_reg (
.clk (clk),
.reset (reset),
.enable (enable),
.data_in (data_in),
.data_out (data_out)
);
end
endmodule
`TRACING_ON