add vcd_reg_dump example

examples/vcd_reg_dump.rs

@@ -0,0 +1,44 @@
+use logical::dump::Vcd;
+use logical::{Ieee1164, LogicVector};
+
+fn main() {
+    let v = LogicVector::with_value(5, 8).unwrap();
+    assert_eq!(v.width(), 8);
+    assert_eq!(v, 5);
+
+    let mut dumper = Vcd::new("VCD Example");
+    let mut foo: LogicVector;
+
+    foo = vec![Ieee1164::_Z; 16].into();
+    dumper.serialize_logivector("foo", &foo);
+    dumper.tick();
+
+    foo = vec![Ieee1164::_U; 16].into();
+    dumper.serialize_logivector("foo", &foo);
+    dumper.tick();
+
+    foo = vec![Ieee1164::_X; 16].into();
+    dumper.serialize_logivector("foo", &foo);
+    dumper.tick();
+
+    foo = vec![Ieee1164::_W; 16].into();
+    dumper.serialize_logivector("foo", &foo);
+    dumper.tick();
+
+    foo = vec![Ieee1164::_D; 16].into();
+    dumper.serialize_logivector("foo", &foo);
+    dumper.tick();
+
+    foo = vec![Ieee1164::_1; 16].into();
+    dumper.serialize_logivector("foo", &foo);
+    dumper.tick();
+
+    let one = LogicVector::with_value(1, 16).unwrap();
+    for _ in 0..90 {
+        dumper.serialize_logivector("foo", &foo);
+        dumper.tick();
+        foo = (foo + &one).unwrap();
+    }
+
+    dumper.dump("/home/marcel/b.vcd").unwrap();
+}