cpu

Documentation

Overview

Package cpu provides general CPU related type support.

Index

• type AddressingInfo
• type Instruction
  • func (ins Instruction) HasAddressing(flags ...Mode) bool
• type Opcode
  • func (opcode Opcode) ReadWritesMemory(memoryReadWriteInstructions map[string]struct{}) bool
  • func (opcode Opcode) ReadsMemory(memoryReadInstructions map[string]struct{}) bool
  • func (opcode Opcode) WritesMemory(memoryWriteInstructions map[string]struct{}) bool

Types

type AddressingInfo

type AddressingInfo struct {
	Opcode byte
	Size   byte
}

AddressingInfo contains the opcode and timing info for an instruction addressing mode.

type Instruction

type Instruction struct {
	Name       string
	Unofficial bool

	// instruction has no parameters
	NoParamFunc func()
	// instruction has parameters
	ParamFunc func(params ...any)

	// maps addressing mode to cpu cycles
	Addressing map[Mode]AddressingInfo
}

Instruction contains information about a NES CPU instruction.

func (Instruction) HasAddressing

func (ins Instruction) HasAddressing(flags ...Mode) bool

HasAddressing returns whether the instruction has any of the passed addressing modes.

type Opcode

type Opcode struct {
	Instruction    *Instruction
	Addressing     Mode
	Timing         byte
	PageCrossCycle bool
}

Opcode is a NES CPU opcode that contains the instruction info and used addressing mode.

func (Opcode) ReadWritesMemory

func (opcode Opcode) ReadWritesMemory(memoryReadWriteInstructions map[string]struct{}) bool

ReadWritesMemory returns whether the instruction accesses memory reading and writing.

func (Opcode) ReadsMemory

func (opcode Opcode) ReadsMemory(memoryReadInstructions map[string]struct{}) bool

ReadsMemory returns whether the instruction accesses memory reading.

func (Opcode) WritesMemory

func (opcode Opcode) WritesMemory(memoryWriteInstructions map[string]struct{}) bool

WritesMemory returns whether the instruction accesses memory writing.