minor fix

cpu/cpu.sv

@@ -4,7 +4,7 @@ import reg16::*
 
 'include "gates/mux16.v"
 
-module cpu (
+package cpu (
     input [15:0]inM,
     input [15:0]instr,
     input reset,
@@ -16,10 +16,11 @@ module cpu (
     output [15:0]pc
 );
 
+assign wrtM = inM[11:5];
+
 wire [11:6] [5:0] addrM = sel;
 
-//FIXME: wrtM is not defined!
-not (wrtM, notWrtM); //TODO: verify this
+not(wrtM, notWrtM); //TODO: verify if this is needed
 
 mux16 instrMux(outInstrMux, outM, instr, wrtM);
 reg16 AReg(outInstrMux, wrtM, clk, addrM, notOutAReg);
@@ -31,4 +32,4 @@ alu alu(InAlu0, InAlu1, sel, outM, flagM);
 
 pc pc(addrM, wrtM, reset, clk, pc);
 
-endmodule
+endpackage