From 3470d7c7e045d0271593be90115a629418f6258c Mon Sep 17 00:00:00 2001
From: Steve Schnepp <steve.schnepp@pwkf.org>
Date: Sun, 17 Sep 2023 18:01:27 +0200
Subject: [PATCH] dump VCD file

---
 logicboard.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 65 insertions(+), 4 deletions(-)

diff --git a/logicboard.c b/logicboard.c
index 79885a7..3bc4d3f 100644
--- a/logicboard.c
+++ b/logicboard.c
@@ -40,6 +40,10 @@ static unsigned char shiftregisters[4*4];
 static int audiotick = 0;
 static FILE *audioout = NULL;
 
+char vcd_in_filename[64];
+char vcd_out_filename[64];
+FILE *vcd_out;
+
 // for the 2x16 character display
 static unsigned char chardisplayram[0x80];
 static unsigned char chardisplaycgram[0x40];
@@ -66,6 +70,15 @@ static void closeaudio(void)
     fclose(audioout);
 }
 
+char *itob(int v) {
+	static char BUF[8];
+	for (int i = 0; i < 8; i ++) {
+		int set = v & (1<<(8-i));
+		BUF[i] = set ? '1' : '0';
+	}
+	return BUF;
+}
+
 void logicboard_tick(struct em8051 *aCPU)
 {
     int i;
@@ -417,10 +430,55 @@ void logicboard_tick(struct em8051 *aCPU)
             audiotick -= opt_clock_hz / (44100 * 12);
         }
     }
-    oldports[0] = aCPU->mSFR[REG_P0];
-    oldports[1] = aCPU->mSFR[REG_P1];
-    oldports[2] = aCPU->mSFR[REG_P2];
-    oldports[3] = aCPU->mSFR[REG_P3];
+
+    // Dump ports as VCF
+    if (!vcd_out_filename[0]) {
+	strcpy(vcd_out_filename, "out.vcd");
+        vcd_out = fopen(vcd_out_filename, "wb");
+
+	fprintf(vcd_out, "$version Generated by emu8051 $end\n");
+#if 0
+	fprintf(vcd_out, "$date Wed Jun  7 11:35:32 2017 $end\n");
+#endif
+	fprintf(vcd_out, "$comment this is highly experimental $end\n");
+	fprintf(vcd_out, "$timescale 1ns $end\n");
+
+	fprintf(vcd_out, "$var wire 8 P0 P0 $end\n");
+	fprintf(vcd_out, "$var wire 8 P1 P1 $end\n");
+	fprintf(vcd_out, "$var wire 8 P2 P2 $end\n");
+	fprintf(vcd_out, "$var wire 8 P3 P3 $end\n");
+
+#if 0
+	fprintf(vcd_out, "$var wire 1 r RX $end\n");
+	fprintf(vcd_out, "$var wire 1 t TX $end\n");
+#endif
+
+	fprintf(vcd_out, "$dumpvars\n");
+	fprintf(vcd_out, "bXXXXXXXX P0\n");
+	fprintf(vcd_out, "bXXXXXXXX P1\n");
+	fprintf(vcd_out, "bXXXXXXXX P2\n");
+	fprintf(vcd_out, "bXXXXXXXX P3\n");
+	fprintf(vcd_out, "$end\n");
+    }
+
+    static int last_emitted_time = -1;
+
+    for (int idx = 0; idx < 4; idx ++) {
+	    int current_time = clocks * (1.0f / opt_clock_hz * 1000 * 1000 * 1000);
+	    int current_value = aCPU->mSFR[REG_P0 + idx * 0x10];
+	    if (oldports[idx] == current_value) continue;
+	    if (last_emitted_time != current_time) {
+		fprintf(vcd_out, "#%d \n", current_time);
+		last_emitted_time = current_time;
+	    }
+	    fprintf(vcd_out, "b%8s P%d\n", itob(current_value), idx);
+	    oldports[idx] = current_value;
+#if 0
+	    if (idx==3) fprintf(vcd_out, "r%d\n", !!(aCPU->mSFR[REG_P3] & 0x01));
+	    if (idx==3) fprintf(vcd_out, "t%d\n", !!(aCPU->mSFR[REG_P3] & 0x02));
+#endif
+    }
+    fflush(vcd_out);
 }
 
 static void logicboard_render_7segs(struct em8051 *aCPU)
@@ -750,5 +808,8 @@ void logicboard_update(struct em8051 *aCPU)
 		break;
     }
 
+    mvprintw(18, 4, "in  VCD file : %s", vcd_in_filename);
+    mvprintw(19, 4, "out VCD file : %s", vcd_out_filename);
+
     refresh();
 }