// Execute an instruction cycle // Fetch an instruction // Decode the instruction opcode // Execute the instruction // void instruction_cycle(CPU *cpu) { // Get current instruction to execute and its location, // echo them out. // Address old_pc = cpu->pgm_counter; fetch_instr(cpu); printf("x%04hX: x%04hX \n", old_pc, cpu->instr_reg); // Execute instruction; set halt = 1 if execution is to stop // (TRAP HALT or internal error). // switch (op(cpu->instr_reg)) { case 0: instr_BR(cpu); break; case 1: instr_ADD(cpu); break; case 2: instr_LD(cpu); break; case 3: instr_ST(cpu); break; case 4: instr_JSR(cpu); break; case 5: instr_AND(cpu); break; case 6: instr_LDR(cpu); break; case 7: instr_STR(cpu); break; case 8: instr_RTI(cpu); break; case 9: instr_NOT(cpu); break; case 10: instr_LDI(cpu); break; case 11: instr_STI(cpu); break; case 12: instr_RTI(cpu); break; case 13: instr_STI(cpu); break; case 14: instr_LEA(cpu); break; case 15: instr_TRAP(cpu); break; default: printf("Bad opcode: %d; quitting\n", op(cpu->instr_reg)); cpu->running = 0; break; } }
// Execute an instruction cycle // Fetch an instruction // Decode the instruction opcode // Execute the instruction // void instruction_cycle(CPU *cpu) { // Get current instruction to execute and its loc, // echo them out. // Address old_pc = cpu->pgm_counter; fetch_instr(cpu); printf("x%04hX: x%04hX ", old_pc, cpu->instr_reg); // Execute instruction; set cpu running = 0 if CPU execution // is to stop (because of TRAP HALT or an internal error). // //>>>>>>>>>>>>>>>>SWITCH CASE MUST BE EDITED Compliar error switch (cpu->instr_reg) { case 0: instr_BR(cpu); break; case 1: instr_ADD(cpu); break; case 2: instr_LD(cpu); break; case 3: instr_ST(cpu); break; case 4: instr_JSR(cpu); break; case 5: instr_AND(cpu); break; case 6: instr_LDR(cpu); break; case 7: instr_STR(cpu); break; case 8: instr_RTI(cpu); break; case 9: instr_NOT(cpu); break; case 10: instr_LDI(cpu); break; case 11: instr_STI(cpu); break; case 12: instr_RTI(cpu); break; case 13: instr_STI(cpu); break; case 14: instr_LEA(cpu); break; case 15: instr_TRAP(cpu); break; default: printf("Bad opcode: %d; quitting\n", op(cpu->instr_reg)); cpu->running = 0; break; } }
// Execute an instruction cycle // Fetch an instruction // Decode the instruction opcode // Execute the instruction // void instruction_cycle(CPU *cpu) { // Get current instruction to execute and its location, // echo them out. // Address old_pc = cpu->pgm_counter; fetch_instr(cpu); printf("x%04hX: x%04hX ", old_pc, cpu->instr_reg); // Execute instruction; set halt = 1 if execution is to stop // (TRAP HALT or internal error). // switch ((cpu->instr_reg)) // ** Note ** place "op(cpu->instr_reg))" { case 0: instr_BR(cpu); break; default: printf("Bad opcode: %d; quitting\n", (cpu->instr_reg)); // ** Note ** place "op(cpu->instr_reg))" cpu->running = 0; } }
void instruction_cycle(CPU *cpu, int order) { // Get current instruction to execute and its location, // echo them out. // Address old_pc = cpu->memory[cpu->pgm_counter+1]; // OLD: cpu->pgm_counter fetch_instr(cpu); int op_code = 0; u_reg = ((unsigned short int)(cpu->instr_reg)); op_code = u_reg/4096; unsigned short movement1 = (old_pc << 4); unsigned short movement2 = (old_pc << 7); unsigned short movement3 = (old_pc << 12); unsigned short movement4 = (old_pc << 7); unsigned short movement5 = (old_pc << 13); Commands.opCode = (old_pc >> 12); // Finished Commands.intRest = (old_pc << 8); // Finished Commands.trap = (Commands.intRest >> 8); // Finished Commands.NZP = (movement1 >> 13); Commands.offset = (movement2 >> 7); Commands.last = (movement3 >> 12); Commands.Src1 = (movement4 >> 6); Commands.Src2 = (movement5 >> 13); /* Tests Output bit shifts printf("\nShowing whats in memory, dividing integers:\n\n"); printf("First Hex: %hX\n", Commands.opCode); printf("Second Hex: %hX\n", Commands.intSecond); //printf("Remaining Hex: %hX\n", intRest); printf("NZP value: %hX\n", Commands.NZP); printf("offset value: %hX\n", Commands.offset); printf("Trap value (last 2 digits): %hX\n", Commands.trap); printf("Last value: %hX\n", Commands.last); */ // Execute instruction; set halt = 1 if execution is to stop // (TRAP HALT or internal error). // switch ((Commands.opCode)) // ** Note ** place "op(cpu->instr_reg))" { case 0: if (Commands.NZP > 0){ // Command loop that accounts for P and Z // Removed because of the lack of time /*if(Commands.NZP == 2){ printf("BRZ 3, CC = P, no go to\n"); //cpu->pgm_counter--; } else{ */ order ++; printf("x%04X: x%04hX ", order, old_pc); // print location cpu->pgm_counter = cpu->pgm_counter + Commands.last; printf("BR %d, CC = Z, go to x%04X+%d = x%04X\n", Commands.last, order, (signed short)Commands.last, (order + Commands.last)); order = order + Commands.last; } else{ instr_BR(cpu); } break; case 1: printf("x%04X: x%04hX ", order, old_pc); instr_ADD(cpu); break; case 2: printf("x%04X: x%04hX ", order, old_pc); instr_LD(cpu, order); break; case 3: printf("x%04X: x%04hX ", order, old_pc); instr_ST(cpu, order); break; case 4: printf("x%04X: x%04hX ", order, old_pc); instr_JSR(cpu); break; case 5: printf("x%04X: x%04hX ", order, old_pc); instr_AND(cpu); break; case 6: printf("x%04X: x%04hX ", order, old_pc); instr_LDR(cpu); break; case 7: printf("x%04X: x%04hX ", order, old_pc); instr_STR(cpu); break; case 8: printf("x%04X: x%04hX ", order, old_pc); instr_RTI(cpu); break; case 9: printf("x%04X: x%04hX ", order, old_pc); instr_NOT(cpu); break; case 10: printf("x%04X: x%04hX ", order, old_pc); instr_LDI(cpu); break; case 11: printf("x%04X: x%04hX ", order, old_pc); instr_STI(cpu); break; case 12: printf("x%04X: x%04hX ", order, old_pc); instr_JMP(cpu); break; case 13: printf("x%04X: x%04hX ", order, old_pc); instr_err(cpu); break; case 14: printf("x%04X: x%04hX ", order, old_pc); instr_LEA(cpu, order); break; case 15: printf("x%04X: x%04hX ", order, old_pc); instr_TRAP(cpu); break; default: printf("Bad opcode: %d; quitting\n", (Commands.opCode)); // ** Note ** place "op(cpu->instr_reg))" cpu->running = 0; } old_pc++; }