Init nand2tetris

projects/03/a/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/03/a/PC.hdl
+
+/**
+ * A 16-bit counter with load and reset control bits.
+ * if      (reset[t] == 1) out[t+1] = 0
+ * else if (load[t] == 1)  out[t+1] = in[t]
+ * else if (inc[t] == 1)   out[t+1] = out[t] + 1  (integer addition)
+ * else                    out[t+1] = out[t]
+ */
+
+CHIP PC {
+    IN in[16],load,inc,reset;
+    OUT out[16];
+
+
+    PARTS:
+
+    //Inc, Rückkopplung des out und +1
+    Inc16(in=toinc, out=outinc);
+
+    //inc-flag
+    Mux16(a=outtomux, b=outinc, sel=inc, out=outmuxinc);
+    //load-flag, wenn 1 dann schiebe in auf das in des Registers
+    Mux16(a=outmuxinc, b=in, sel=load, out=outmuxload);
+    //reset-flag
+    Mux16(a=outmuxload, b=false, sel=reset, out=outmuxreset);
+    //Register
+    Register(in=outmuxreset, load=true, out=out, out=toinc, out=outtomux);
+}