update lsfr preset; filter verilog boring errors

doc/notes.txt

@@ -11,7 +11,7 @@ TODO:
 - debugging inside of bank switching??? relocated segs?
 - support 6502 test cases
 - DASM: macro forward refs
-- asm: support macro expansion (need addr2line map)
+- asm: support macro expansion
 - support narrow screens
 - show other TIA internal values
 - case sensisitvity looking for mismatch variables

presets/verilog/lfsr.v

@@ -3,9 +3,9 @@
 
 module LFSR(clk,reset,enable,lfsr);
   
-  parameter NBITS  = 8;
   parameter TAPS   = 8'b11101;
   parameter INVERT = 0;
+  localparam NBITS  = $size(TAPS);
   
   input clk, reset;
   input enable;

presets/verilog/sound_generator.v

@@ -26,7 +26,7 @@ module sound_generator(clk, reset, spkr,
 
   reg [15:0] lfsr;		// LFSR output
   
-  LFSR #(16,16'b1000000001011,0) lfsr_gen(
+  LFSR #(16'b1000000001011,0) lfsr_gen(
     .clk(clk),
     .reset(reset),
     .enable(div16 == 0 && noise_count == 0),

presets/verilog/starfield.v

@@ -24,7 +24,7 @@ module starfield_top(clk, reset, hsync, vsync, rgb);
   wire star_enable = !hpos[8] & !vpos[8];
   
   // LFSR with period = 2^16-1 = 256*256-1
-  LFSR #(16,16'b1000000001011,0) lfsr_gen(
+  LFSR #(16'b1000000001011,0) lfsr_gen(
     .clk(clk),
     .reset(reset),
     .enable(star_enable),

src/worker/workermain.js

@@ -1189,6 +1189,9 @@ function compileVerilator(step) {
     errors.push({line:0,msg:"Compiler internal error: " + e});
   }
   endtime("compile");
+  // remove boring errors
+  errors = errors.filter(function(e) { return !/Exiting due to \d+/.exec(e.msg); }, errors);
+  errors = errors.filter(function(e) { return !/Use ["][/][*]/.exec(e.msg); }, errors);
   if (errors.length) {
     return {errors:errors};
   }

test/cli/testworker.js

@@ -162,7 +162,7 @@ describe('Worker', function() {
       assert.ok(fn);
       done(err, msg);
     };
-    doBuild(msgs, done2, 2782, 0, 0);
+    doBuild(msgs, done2, 2799, 0, 0);
   });
   it('should compile verilog inline assembler (JSASM)', function(done) {
     var csource = ab2str(fs.readFileSync('presets/verilog/racing_game_cpu.v'));
@@ -179,7 +179,7 @@ describe('Worker', function() {
       assert.ok(fn);
       done(err, msg);
     };
-    doBuild(msgs, done2, 49317, 0, 0);
+    doBuild(msgs, done2, 49357, 0, 0);
   });
   it('should compile verilog assembler file (JSASM)', function(done) {
     var csource = ab2str(fs.readFileSync('presets/verilog/test2.asm'));

tools/lfsrcalc.py

@@ -1,8 +1,10 @@
 #!/usr/bin/python
 
-print "Period,nbits,feedback,mask"
+MAXBITS=16
 
-for n in range(1,18):
+print("Period,nbits,feedback,mask")
+
+for n in range(1,MAXBITS):
     mask = (1<<n)-1
     hibit = (1<<(n-1))
     for i in range(0,1<<n):
@@ -25,4 +27,4 @@ for n in range(1,18):
                 seqindex = seq.index(x)
                 seqlen = len(seq) - seqindex
                 if seqlen>1:
-                    print seqlen, "#(%d,%d'%s,%d)" % (n,n,bin(i)[1:],invert), seqindex
+                    print(seqlen, "#(%d,%d'%s,%d)" % (n,n,bin(i)[1:],invert), seqindex)

tools/lfsrcalc2.js

@@ -0,0 +1,42 @@
+"use strict";
+
+var BEST={}
+
+var MAXBITS=17
+//MAXBITS=12
+
+for (var n=1; n<MAXBITS; n++) {
+    var mask = (1<<n)-1;
+    var hibit = (1<<(n-1));
+    for (var i=0; i < (1<<n); i++) {
+        for (var invert=0; invert<2; invert++) {
+            var x = 1;
+            var seq = [];
+            var seen = new Map();
+            while (x && !seen.get(x)) {
+                seq.push(x);
+                seen.set(x, true);
+                var feedback = (x & hibit) != 0;
+                x = ((x << 1) & mask);
+                if (invert && !feedback) x ^= i;
+                if (!invert && feedback) x ^= i;
+            }
+            if (x) {
+                var seqindex = seq.indexOf(x);
+                var seqlen = seq.length - seqindex;
+                if (seqlen > 1 && x == 1) {
+                    if (!BEST[seqlen] || n < BEST[seqlen].n) {
+                        BEST[seqlen] = {n:n, i:i, invert:invert};
+                        //console.log(seqlen + "\t" + n + "\t" + i.toString(2) + "\t" + x.toString(2));
+                    }
+                }
+            }
+        }
+    }
+}
+
+for (var seqlen in BEST) {
+    var b = BEST[seqlen];
+    console.log(seqlen+" &\t@"+b.n+"'b"+b.i.toString(2)+","+b.invert+"@ \\\\");
+}
+