code refactoring for Vivado compatibility

hw/rtl/libs/VX_shift_register.sv

@@ -0,0 +1,141 @@
+`include "VX_platform.vh"
+
+`TRACING_OFF
+module VX_shift_register_nr #( 
+    parameter DATAW  = 1,
+    parameter DEPTH  = 1,
+    parameter NTAPS  = 1,
+    parameter DEPTHW = $clog2(DEPTH),
+    parameter [(DEPTHW*NTAPS)-1:0] TAPS = {NTAPS{DEPTHW'(DEPTH-1)}}
+) (
+    input wire clk,
+    input wire enable,
+    input wire [DATAW-1:0]          data_in,
+    output wire [(NTAPS*DATAW)-1:0] data_out
+);
+    reg [DEPTH-1:0][DATAW-1:0] entries;
+
+    always @(posedge clk) begin
+        if (enable) begin                    
+            for (integer i = DEPTH-1; i > 0; --i)
+                entries[i] <= entries[i-1];
+            entries[0] <= data_in;
+        end
+    end
+
+    for (genvar i = 0; i < NTAPS; ++i) begin
+        assign data_out [i*DATAW+:DATAW] = entries [TAPS[i*DEPTHW+:DEPTHW]];
+    end
+
+endmodule
+
+module VX_shift_register_wr #( 
+    parameter DATAW  = 1, 
+    parameter DEPTH  = 1,
+    parameter NTAPS  = 1,
+    parameter DEPTHW = $clog2(DEPTH),
+    parameter [(DEPTHW*NTAPS)-1:0] TAPS = {NTAPS{DEPTHW'(DEPTH-1)}}
+) (
+    input wire clk,
+    input wire reset,
+    input wire enable,
+    input wire [DATAW-1:0]          data_in,
+    output wire [(NTAPS*DATAW)-1:0] data_out
+);
+    reg [DEPTH-1:0][DATAW-1:0] entries;
+
+    always @(posedge clk) begin
+        if (reset) begin
+            entries <= '0;
+        end else if (enable) begin                    
+            for (integer i = DEPTH-1; i > 0; --i)
+                entries[i] <= entries[i-1];
+            entries[0] <= data_in;
+        end
+    end
+
+    for (genvar i = 0; i < NTAPS; ++i) begin
+        assign data_out [i*DATAW+:DATAW] = entries [TAPS[i*DEPTHW+:DEPTHW]];
+    end
+
+endmodule
+
+module VX_shift_register #( 
+    parameter DATAW  = 1, 
+    parameter RESETW = 0,
+    parameter DEPTH  = 1,
+    parameter NTAPS  = 1,
+    parameter DEPTHW = $clog2(DEPTH),
+    parameter [(DEPTHW*NTAPS)-1:0] TAPS = {NTAPS{DEPTHW'(DEPTH-1)}}
+) (
+    input wire clk,
+    input wire reset,
+    input wire enable,
+    input wire [DATAW-1:0]          data_in,
+    output wire [(NTAPS*DATAW)-1:0] data_out
+);
+    if (RESETW != 0) begin
+        if (RESETW == DATAW) begin
+    
+            VX_shift_register_wr #(
+                .DATAW (DATAW),
+                .DEPTH (DEPTH),
+                .NTAPS (NTAPS),
+                .TAPS  (TAPS)
+            ) sr (
+                .clk      (clk),
+                .reset    (reset),
+                .enable   (enable),
+                .data_in  (data_in),
+                .data_out (data_out)
+            );
+    
+        end else begin
+    
+            VX_shift_register_wr #(
+                .DATAW (RESETW),
+                .DEPTH (DEPTH),
+                .NTAPS (NTAPS),
+                .TAPS  (TAPS)
+            ) sr_wr (
+                .clk      (clk),
+                .reset    (reset),
+                .enable   (enable),
+                .data_in  (data_in[DATAW-1:DATAW-RESETW]),
+                .data_out (data_out[DATAW-1:DATAW-RESETW])
+            );
+
+            VX_shift_register_nr #(
+                .DATAW (DATAW-RESETW),
+                .DEPTH (DEPTH),
+                .NTAPS (NTAPS),
+                .TAPS  (TAPS)
+            ) sr_nr (
+                .clk      (clk),
+                .enable   (enable),
+                .data_in  (data_in[DATAW-RESETW-1:0]),
+                .data_out (data_out[DATAW-RESETW-1:0])
+            );
+
+        end
+
+    end else begin        
+
+        `UNUSED_VAR (reset)
+    
+        VX_shift_register_nr #(
+            .DATAW (DATAW),
+            .DEPTH (DEPTH),
+            .NTAPS (NTAPS),
+            .TAPS  (TAPS)
+        ) sr (
+            .clk      (clk),
+            .enable   (enable),
+            .data_in  (data_in),
+            .data_out (data_out)
+        );
+
+    end    
+
+endmodule
+`TRACING_ON