Introduction to the 8085 Instruction Set
The 8085 is an 8-bit microprocessor that was first introduced by Intel in 1976. It has a basic instruction set consisting of 246 instructions, which are divided into the following categories:
Data Transfer Instructions:
- MOV: Move register/memory to register/memory
- MVI: Move immediate data to register/memory
- LXI: Load immediate data into register pair
- LDA: Load accumulator with memory
- STA: Store accumulator in memory
- LHLD: Load HL pair direct
- SHLD: Store HL pair direct
- XCHG: Exchange H and L with D and E
Arithmetic Instructions:
- ADD: Add register/memory to accumulator
- ADC: Add register/memory and carry to accumulator
- ADI: Add immediate data to accumulator
- ACI: Add immediate data and carry to accumulator
- SUB: Subtract register/memory from accumulator
- SBB: Subtract register/memory and borrow from accumulator
- SUI: Subtract immediate data from accumulator
- SBI: Subtract immediate data and borrow from accumulator
- INR: Increment register/memory
- DCR: Decrement register/memory
- INX: Increment register pair
- DCX: Decrement register pair
- DAD: Double register pair and add
Logical Instructions:
- ANA: AND register/memory with accumulator
- ANI: AND immediate data with accumulator
- ORA: OR register/memory with accumulator
- ORI: OR immediate data with accumulator
- XRA: XOR register/memory with accumulator
- XRI: XOR immediate data with accumulator
- CMP: Compare register/memory with accumulator
- CPI: Compare immediate data with accumulator
- CMA: Complement accumulator
- STC: Set carry flag
- CMC: Complement carry flag
Branching Instructions:
- JMP: Jump to memory address
- JC: Jump on carry flag set
- JNC: Jump on carry flag reset
- JZ: Jump on zero flag set
- JNZ: Jump on zero flag reset
- JP: Jump on positive sign flag
- JM: Jump on minus sign flag
- JPE: Jump on parity flag set
- JPO: Jump on parity flag reset
- CALL: Call subroutine at memory address
- CC: Call subroutine on carry flag set
- CNC: Call subroutine on carry flag reset
- CZ: Call subroutine on zero flag set
- CNZ: Call subroutine on zero flag reset
- CP: Call subroutine on positive sign flag
- CM: Call subroutine on minus sign flag
- CPE: Call subroutine on parity flag set
- CPO: Call subroutine on parity flag reset
- RET: Return from subroutine
- RC: Return on carry flag set
- RNC: Return on carry flag reset
- RZ: Return on zero flag set
- RNZ: Return on zero flag reset
- RP: Return on positive sign flag
- RM: Return on minus sign flag
- RPE: Return on parity flag set
- RPO: Return on parity flag reset
Stack, I/O, and Machine Control Instructions:
- PUSH: Push register pair onto stack
- POP: Pop register pair from stack
- XTHL: Exchange stack top with H and L
- SPHL: Load HL pair direct to stack pointer
- EI: Enable interrupts
- DI: Disable interrupts
- IN: Input data from I/O port
- OUT: Output data to I/O port
- HLT: Halt the processor
- NOP: No operation
Note that this is not an exhaustive list of all the instructions available in the 8085 instruction set, but it includes the most commonly
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