ad_dds_cordic: Move the shifting operation

Perform the shifting operation before addition/subtraction in a
rotation stage. In the previous method, the result of the arithmetic
operation was shifted and the outcome was presented to the next stage.
In this way, data connections will be reduced between pipeline stages

library/common/ad_dds_cordic_pipe.v

@@ -53,14 +53,10 @@ module ad_dds_cordic_pipe#(
   (* keep = "TRUE" *) input             [    DW-1:0] dataa_x,
   (* keep = "TRUE" *) input             [    DW-1:0] dataa_y,
   (* keep = "TRUE" *) input             [    DW-1:0] dataa_z,
-  (* keep = "TRUE" *) input             [    DW-1:0] datab_x,
-  (* keep = "TRUE" *) input             [    DW-1:0] datab_y,
   (* keep = "TRUE" *) input             [    DW-1:0] datab_z,
   (* keep = "TRUE" *) output reg        [    DW-1:0] result_x,
   (* keep = "TRUE" *) output reg        [    DW-1:0] result_y,
   (* keep = "TRUE" *) output reg        [    DW-1:0] result_z,
-                      output     signed [    DW-1:0] sgn_shift_x,
-                      output     signed [    DW-1:0] sgn_shift_y,
                       input             [DELAY_DW:1] data_delay_in,
                       output            [DELAY_DW:1] data_delay_out);
 
@@ -70,21 +66,23 @@ module ad_dds_cordic_pipe#(
 
   // Wires Declarations
 
-  wire dir_inv = ~dir;
+  wire  [    DW-1:0]  sgn_shift_x;
+  wire  [    DW-1:0]  sgn_shift_y;
+  wire                dir_inv = ~dir;
+
+  // Previous stage shift
+
+  assign sgn_shift_x = {{SHIFT{dataa_x[DW-1]}}, dataa_x[DW-1:SHIFT]};
+  assign sgn_shift_y = {{SHIFT{dataa_y[DW-1]}}, dataa_y[DW-1:SHIFT]};
 
   // Stage rotation
 
   always @(posedge clk) begin
-    result_x <= dataa_x + ({DW{dir_inv}} ^ datab_y) + dir_inv;
-    result_y <= dataa_y + ({DW{dir}}     ^ datab_x) + dir;
-    result_z <= dataa_z + ({DW{dir_inv}} ^ datab_z) + dir_inv;
+    result_x <= dataa_x + ({DW{dir_inv}} ^ sgn_shift_y) + dir_inv;
+    result_y <= dataa_y + ({DW{dir}}     ^ sgn_shift_x) + dir;
+    result_z <= dataa_z + ({DW{dir_inv}} ^     datab_z) + dir_inv;
   end
 
-  // Stage shift
-
-  assign sgn_shift_x = {{SHIFT{result_x[DW-1]}}, result_x[DW-1:SHIFT]};
-  assign sgn_shift_y = {{SHIFT{result_y[DW-1]}}, result_y[DW-1:SHIFT]};
-
   // Delay data (if used)
 
   generate

library/common/ad_dds_sine_cordic.v

@@ -61,21 +61,19 @@ module ad_dds_sine_cordic #(
 
   // Registers Declarations
 
-  reg signed  [CORDIC_DW-1:0] x0  = 'd0;
-  reg signed  [CORDIC_DW-1:0] y0  = 'd0;
-  reg signed  [CORDIC_DW-1:0] z0  = 'd0;
+  reg  [CORDIC_DW-1:0] x0  = 'd0;
+  reg  [CORDIC_DW-1:0] y0  = 'd0;
+  reg  [CORDIC_DW-1:0] z0  = 'd0;
 
   // Wires Declarations
 
-  wire        [CORDIC_DW-1:0] x_value;
-  wire signed [CORDIC_DW-1:0] x_s       [0:CORDIC_DW-1];
-  wire signed [CORDIC_DW-1:0] y_s       [0:CORDIC_DW-1];
-  wire signed [CORDIC_DW-1:0] z_s       [0:CORDIC_DW-1];
-  wire signed [CORDIC_DW-1:0] x_shr_s   [0:CORDIC_DW-1];
-  wire signed [CORDIC_DW-1:0] y_shr_s   [0:CORDIC_DW-1];
-  wire        [ DELAY_DW-1:0] data_in_d [0:CORDIC_DW-1];
-  wire        [CORDIC_DW-1:0] atan_table[0:CORDIC_DW-2];
-  wire        [          1:0] quadrant;
+  wire [CORDIC_DW-1:0] x_value;
+  wire [CORDIC_DW-1:0] x_s       [0:CORDIC_DW-1];
+  wire [CORDIC_DW-1:0] y_s       [0:CORDIC_DW-1];
+  wire [CORDIC_DW-1:0] z_s       [0:CORDIC_DW-1];
+  wire [ DELAY_DW-1:0] data_in_d [0:CORDIC_DW-1];
+  wire [CORDIC_DW-1:0] atan_table[0:CORDIC_DW-2];
+  wire [          1:0] quadrant;
 
   // arc tangent LUT
 
@@ -186,8 +184,6 @@ module ad_dds_sine_cordic #(
   assign x_s[0] = x0;
   assign y_s[0] = y0;
   assign z_s[0] = z0;
-  assign x_shr_s[0] = x0;
-  assign y_shr_s[0] = y0;
   assign data_in_d[0] = ddata_in;
 
   // cordic pipeline
@@ -205,15 +201,11 @@ module ad_dds_sine_cordic #(
         .dataa_x (x_s[i]),
         .dataa_y (y_s[i]),
         .dataa_z (z_s[i]),
-        .datab_x (x_shr_s[i]),
-        .datab_y (y_shr_s[i]),
         .datab_z (atan_table[i]),
         .dir (z_s[i][CORDIC_DW-1]),
         .result_x (x_s[i+1]),
         .result_y (y_s[i+1]),
         .result_z (z_s[i+1]),
-        .sgn_shift_x (x_shr_s[i+1]),
-        .sgn_shift_y (y_shr_s[i+1]),
         .data_delay_in (data_in_d[i]),
         .data_delay_out (data_in_d[i+1])
       );