fetch0:    a_sel=7, b_sel=7, alu_sel=AND, r6_write, mar_sel=LOAD;
fetch1:    a_sel=6, alu_sel=ADDA, c_in, r7_write, read, ir0_sel=LOAD, 
               if wait then goto fetch1 else goto fetch2 endif;
fetch2:    a_sel=7, b_sel=7, alu_sel=AND, r6_write, mar_sel=LOAD;
fetch3:    a_sel=6, alu_sel=ADDA, c_in, r7_write, read, ir1_sel=LOAD, 
               if wait then goto fetch3 else goto fetch4 endif;
fetch4:    goto opcode[IR_OPCODE];
opcode[0]: goto fetch0;                  // no-op
opcode[1]: ri_sel, rj_sel, rk_sel, alu_sel=ADD, goto fetch0; // ri<-rj+rk
opcode[2]: ri_sel, result_sel=IR_CONST8, goto fetch0;        // ri<-const8
opcode[3]: rj_sel, alu_sel=SUBA, r6_write, result_sel=IR_CONST4, if c_out then goto branch else goto fetch0 endif; 
opcode[4]: ri_sel, rj_sel, alu_sel=ADDA, goto fetch0;        // ri<-rj
opcode[5]: rj_sel, alu_sel=ADDA, mar_sel=LOAD, goto opcode5a;  // store: mem[rj]<- rk
opcode[6]: rj_sel, alu_sel=ADDA, mar_sel=LOAD, goto opcode6a;  // load: ri<-mem[rj]
opcode[7]: ri_sel, rj_sel, rk_sel, alu_sel=SUB, c_in, goto fetch0; // subtract
opcode[8]: goto opcode[8];				           // halt
branch:    r7_write, a_sel=7, b_sel=6, alu_sel=ADD, goto fetch0;
opcode5a:  a_sel=5, b_sel=5, alu_sel=SUB, c_in, r5_write, goto opcode5b;
opcode5b:  rk_sel, a_sel=5, alu_sel=OR, mdr_sel=LOAD_ALU, 
               goto memwrite;
memwrite:  write, if wait then goto memwrite else goto fetch0 endif;
opcode6a:  read, mdr_sel=LOAD_MEM, 
               if wait then goto opcode6a else goto opcode6b endif;
opcode6b:  result_sel=MDR, ri_sel, goto fetch0;