Module dez80::instruction

Contains models and functions to define, decode, and format Z80 instructions and their components.

Examples

use std::io::Read;
use dez80::Instruction;

// Initialize a buffer containing raw Z80 opcodes.
let mut data: &[u8] = &[0x00, 0x04, 0x05]; // NOP, INC B, DEC B

// Decode a single instruction from the raw bytes.
if let Ok(instruction) = Instruction::decode_one(&mut data) {
    // Convert the instruction to a string, in its symbolic format.
    assert_eq!("NOP", instruction.to_string());
} else {
    panic!("Could not decode an instruction!");
}

// Decode a sequence of instructions from the remaining bytes.
let instructions = Instruction::decode_all(&mut data);
assert_eq!(2, instructions.len()); // bytes are consumed as they are decoded

for instruction in instructions {
    println!("Decoded {}.", instruction);
}

use dez80::{Instruction, InstructionDecoder};

// Initialize a stateful instruction decoder.
let mut decoder = InstructionDecoder::new();

// Decode a single byte with the decoder.
decoder.push_byte(0x00); // NOP
let result = decoder.try_decode();

// This is a single-byte instruction, so we can verify
// that a valid instruction was returned.
assert!(result.is_ok());
assert_eq!("NOP", result.unwrap().to_string());

// Decode the first byte of a multi-byte instruction.
decoder.push_byte(0xED); // extended instruction
let result = decoder.try_decode();

// No instruction can be decoded from this byte alone.
assert!(result.is_err());

// Decode the second byte of the instruction.
// This time, the instruction can finish decoding.
decoder.push_byte(0x44); // NEG
let result = decoder.try_decode();
assert!(result.is_ok());
assert_eq!("NEG", result.unwrap().to_string());

Structs

Instruction	Represents a single Z80 instruction.
Opcode	Represents an instruction opcode, including prefixes but excluding operands.

Enums

Condition	Represents a prerequisite condition for an instruction.
DecodingState	Represents a state in the decoding process, defined as a combination of the current opcode table, and the role of the next byte to decode. This corresponds to a decoding state that the decoder has yet to perform.
InstructionType	Represents a type of instruction, categorized by mnemonic.
OpcodePrefix	Represents a set of one or two bytes modifying an instruction's opcode.
Operand	Represents a target for data operations. Variants are closely related to Z80 addressing modes.