Complete project 3

Assignments/3_Sequential_Logic/PC.hdl

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+// This file is part of www.nand2tetris.org
+// and the book "The Elements of Computing Systems"
+// by Nisan and Schocken, MIT Press.
+// File name: projects/3/a/PC.hdl
+/**
+ * A 16-bit counter.
+ * if      reset(t): out(t+1) = 0
+ * else if load(t):  out(t+1) = in(t)
+ * else if inc(t):   out(t+1) = out(t) + 1
+ * else              out(t+1) = out(t)
+ */
+CHIP PC {
+    IN in[16], reset, load, inc;
+    OUT out[16];
+    
+    PARTS:
+	Inc16(in=r, out=i);
+    Mux16(a=r, b=i, sel=inc, out=oi);
+    Mux16(a=oi, b=in, sel=load, out=ol);
+    Mux16(a=ol, b=false, sel=reset, out=or);
+    Register(in=or, load=true, out=r, out=out);
+}