Keep in mind that M is the contents of the memory location specified
by HL.
| Opcode | Operand | Description |
|---|
| MVI | [Rd/M], Imm | Move 8-bit immediate |
| LDA | IAddr | Load to 16bit addr to A |
| LDAX | Reg Pair | Indirect load addr to A |
| LXI | Reg Pair, Imm16 | Load 16bit imm to reg pair |
| LHLD | IAddr | Load H-L |
| STA | IAddr | Store A direct |
| STAX | Reg Pair | Store A indirect |
| SHLD | IAddr | Store HL direct |
| XCHG | | Exchange HL with DE |
| SPHL | | SP = HL |
| XTHL | | Exchange HL with top of stack |
| PCHL | | PC=HL |
| PUSH | Reg Pair | Push reg pair in stack |
| POP | Reg Pair | Pop stack into reg-pair |
| OUT | Imm8(port addr) | A to 8-bit port |
| IN | Imm8(port addr) | 8-bit port to A |
Arithmetic results are always stored in the accumulator
| Opcode | Operand | Description | Flags |
|---|
| ADD | [R/M] | A += [R/M] | All |
| ADC | [R/M] | A += [R/M] + CY(Carry) | All |
| ADI | Imm8 | A += Imm8 | All |
| ACI | Imm8 | A += Imm8 + CY(Carry) | All |
| DAD | RegPair | HL += Reg Pair | CY |
| INR | [R/M] | [R/M] += 1 | All |
| INX | RegPair | RegPair += 1 | None |
| SUB | [R/M] | A -= [R/M] | All |
| SBB | [R/M] | A -= [R/M] - CY(Borrow) | All |
| SUI | Imm8 | A -= Imm8 | All |
| SBI | Imm8 | A -= Imm8 - CY(Borrow) | All |
| DCR | [R/M] | [R/M] -= 1 | All |
| DCX | RegPair | RegPair -= 1 | None |
The flags below not in order.
| Flag | Symbol | Description |
|---|
| Zero | Z | Result is 0 |
| Sign | S | If D7 is set |
| Parity | P | Number of 1s is even |
| Carry | CY | Extra bit in result |
| Auxilary Carry | AC | Carry of the 4 LSB arithmetic operation |
| | |
| Opcode | Operand | Description | Flags |
|---|
| CMP | [R/M] | Flags as if A-R: CY=(A<R), Z=(A==R) | CY,Z |
| CPI | Imm8 | <see above> | CY,Z |
| ANA | [R/M] | A &= R | All (CY=0, AC=1) |
| ANI | Imm8 | A &= I | All (CY=0, AC=1) |
| ORA | [R/M] | A |= R | All (CY=0, AC=0) |
| ORI | Imm8 | A |= I | All (CY=0, AC=0) |
| XRA | [R/M] | A ^= R | All (CY=1, AC=1) |
| XRI | Imm8 | A ^= I | All (CY=1, AC=1) |
| RLC | | Rotate left updating CY | CY |
| RAL | | Rotate left through CY | CY |
| RAR | | Rotate right through carry | CY |
| CMA | | Complement A | None |
| CMC | | Complement CY | CY |
| STC | | CY = 1 | CY |
| Opcode | Operand | Description |
|---|
| JMP | IAddr | Jump unconditionally |
| J[flag] | IAddr | Jump conditionally depending on flag (see below) |
| CALL | IAddr | Push next instr in stack and jump to address |
| C[flag] | IAddr | Conditional call depending on flag (see below) |
| RET | | Return unconditionally (use top two bytes of stack) |
| R[flag] | | Return according to flag (see below) |
| RST | 0-7 | Jump to one of 7 addresses: arg * 0x8 |
In conditional branching opcodes we saw extensions to opcodes
denoted by [flag]. Here are their meanings.
| Extension | Description |
|---|
| C | CY |
| NC | Not CY |
| P | Not S (result was positive) |
| M | S (result was negative) |
| Z | Z |
| NZ | Not Z |
| PE | P (Parity Even) |
| PO | not P (Parity Odd) |
| Opcode | Operand | Description |
|---|
| NOP | | No Operation |
| HLT | | Halt. Until interupt or reset. |
| DI | | Disable interrupts (except the TRAP interrupt) |
| EI | | Enable interrupts |
| RIM | | Read interrupt status of 7.5, 6.5 and 5.5 and read serial data input bit |
| SIM | | Set interrupt mask for 7.5, 6.5 and 5.5 and write to the serial data output bit |
- 8214: Priority Interrupt Controller
