Drop a bit from the overflow. Rewrite the assigns.

[mandelfpga.git] / Main.v

diff --git a/Main.v b/Main.v
index b034663f746a74b01b00874ac28c4bdbe5ff17fa..aacfdab6fc91e335f19e8b9f61c12e8509c67263 100644 (file)
--- a/Main.v
+++ b/Main.v
@@ -117,7 +117,7 @@ module MandelUnit(
        wire [14:0] r2, i2, ri, diff;
        wire [15:0] twocdiff;
        wire r2sign, i2sign, risign, dsign;
-       wire [16:0] bigsum;
+       wire [15:0] bigsum;
        wire bigsum_ovf, rin_ovf, iin_ovf, throwaway;
 
        reg [12:0] xd, yd;
@@ -127,12 +127,12 @@ module MandelUnit(
 
        assign ri[0] = 0;
 
-       Multiplier r2m(clk, r[12:0], r[12:0], rsign, rsign, r2[12:0], r2sign, r2[14:13]);
-       Multiplier i2m(clk, i[12:0], i[12:0], isign, isign, i2[12:0], i2sign, i2[14:13]);
-       Multiplier rim(clk, r[12:0], i[12:0], rsign, isign, ri[13:1], risign, {throwaway,ri[14]});
+       Multiplier r2m(clk, r[12:0], r[12:0], rsign, rsign, r2[12:0], r2sign, r2[13]);
+       Multiplier i2m(clk, i[12:0], i[12:0], isign, isign, i2[12:0], i2sign, i2[13]);
+       Multiplier rim(clk, r[12:0], i[12:0], rsign, isign, ri[13:1], risign, ri[14]);
 
        assign bigsum = r2 + i2;
-       assign bigsum_ovf = bigsum[16] | bigsum[15] | bigsum[14];
+       assign bigsum_ovf = bigsum[15] | bigsum[14];
        assign rin_ovf = rd;
        assign iin_ovf = id;
        assign twocdiff = r2 - i2;
@@ -212,7 +212,6 @@ module Mandelbrot(
        assign rxsign = nx[13];
        assign ry = (ny[13] ? -ny[12:0] : ny[12:0]) << scale;
        assign rysign = ny[13];
-       
 
        wire [14:0] mr[`MAXOUTN:0], mi[`MAXOUTN:0];
        wire mrs[`MAXOUTN:0], mis[`MAXOUTN:0];
@@ -232,36 +231,36 @@ module Mandelbrot(
        
        reg [2:0] state = 3'b001;       // One-hot encoded state.
        
-       assign initx = state[0] ? rx :
-                      state[1] ? stagex[1] :
-                      stagex[2];
-       assign inity = state[0] ? ry :
-                      state[1] ? stagey[1] :
-                      stagey[2];
-       assign initr = state[0] ? rx :
-                      state[1] ? stager[1] :
-                      stager[2];
-       assign initi = state[0] ? ry :
-                      state[1] ? stagei[1] :
-                      stagei[2];
-       assign initxs = state[0] ? rxsign :
-                       state[1] ? stagexs[1] :
-                       stagexs[2];
-       assign initys = state[0] ? rysign :
-                       state[1] ? stageys[1] :
-                       stageys[2];
-       assign initrs = state[0] ? rxsign :
-                       state[1] ? stagers[1] :
-                       stagers[2];
-       assign initis = state[0] ? rysign :
-                       state[1] ? stageis[1] :
-                       stageis[2];
-       assign initb = state[0] ? 8'b11111111 :
-                      state[1] ? stageb[1] :
-                      stageb[2];
-       assign initci = state[0] ? 8'b00000000 :
-                       state[1] ? stageci[1] : 
-                       stageci[2];
+       assign initx = (state[0]) ? rx :
+                      (state[1]) ? stagex[1] :
+                      (state[2]) ? stagex[2] : 0;
+       assign inity = (state[0]) ? ry :
+                      (state[1]) ? stagey[1] :
+                      (state[2]) ? stagey[2] : 0;
+       assign initr = (state[0]) ? rx :
+                      (state[1]) ? stager[1] :
+                      (state[2]) ? stager[2] : 0;
+       assign initi = (state[0]) ? ry :
+                      (state[1]) ? stagei[1] :
+                      (state[2]) ? stagei[2] : 0;
+       assign initxs = (state[0]) ? rxsign :
+                       (state[1]) ? stagexs[1] :
+                       (state[2]) ? stagexs[2] : 0;
+       assign initys = (state[0]) ? rysign :
+                       (state[1]) ? stageys[1] :
+                       (state[2]) ? stageys[2] : 0;
+       assign initrs = (state[0]) ? rxsign :
+                       (state[1]) ? stagers[1] :
+                       (state[2]) ? stagers[2] : 0;
+       assign initis = (state[0]) ? rysign :
+                       (state[1]) ? stageis[1] :
+                       (state[2]) ? stageis[2] : 0;
+       assign initb = (state[0]) ? 8'b11111111 :
+                      (state[1]) ? stageb[1] :
+                      (state[2]) ? stageb[2] : 0;
+       assign initci = (state[0]) ? 8'b00000000 :
+                       (state[1]) ? stageci[1] : 
+                       (state[2]) ? stageci[2] : 0;
        
        reg [7:0] out;
        
@@ -277,7 +276,11 @@ module Mandelbrot(
                if (lastneg && pixclk)  // If a pixclk has happened, the state should be reset.
                        state <= 3'b100;
                else                                            // Otherwise, just poke it forward.
-                       state <= {state[1], state[0], state[2]};
+                       case(state)
+                       3'b001: state <= 3'b010;
+                       3'b010: state <= 3'b100;
+                       3'b100: state <= 3'b001;
+                       endcase
        
                // Data output handling
                if (state[0]) begin