cpu

Documentation

Index

• type Flag
• type Mos6502
  • func NewMos6502() *Mos6502
  • func (cpu *Mos6502) Clock()
  • func (cpu *Mos6502) ConnectBus(b *bus.Bus)
  • func (cpu *Mos6502) Disassemble(addressStart uint16, addressStop uint16) map[uint16]string
  • func (cpu *Mos6502) GetAccumulator() byte
  • func (cpu *Mos6502) GetProgramCounter() uint16
  • func (cpu *Mos6502) GetStackPointer() byte
  • func (cpu *Mos6502) GetStatusFlag(f Flag) byte
  • func (cpu *Mos6502) GetX() byte
  • func (cpu *Mos6502) GetY() byte
  • func (cpu *Mos6502) InterruptRequest()
  • func (cpu *Mos6502) NonMaskableInterrupt()
  • func (cpu *Mos6502) Reset()

Types

type Flag

type Flag byte

Flag is the possible different status flags for the CPU.

const (
	C Flag = 1 << iota // C is the Carry Bit flag.
	Z                  // Z is the Zero flag.
	I                  // I is the Disable Interrupts flag.
	D                  // D is the Decimal Mode flag.
	B                  // B is the Break flag.
	U                  // U is the Unused flag.
	V                  // V is the Overflow flag.
	N                  // N is the Negative flag.
)

Mos6502 Status Flags

type Mos6502

type Mos6502 struct {
	// contains filtered or unexported fields
}

Mos6502 represents a Mos 6502 CPU.

func NewMos6502

func NewMos6502() *Mos6502

NewMos6502 constructs and returns a pointer to an instance of Mos6502.

func (*Mos6502) Clock

func (cpu *Mos6502) Clock()

Clock is the clock signal.

func (*Mos6502) ConnectBus

func (cpu *Mos6502) ConnectBus(b *bus.Bus)

ConnectBus connects the CPU to a Bus.

func (*Mos6502) Disassemble

func (cpu *Mos6502) Disassemble(addressStart uint16, addressStop uint16) map[uint16]string

Disassemble builds a map of assembly strings for a given range of addresses.

func (*Mos6502) GetAccumulator

func (cpu *Mos6502) GetAccumulator() byte

GetAccumulator returns the current value of the Accumulator Register.

func (*Mos6502) GetProgramCounter

func (cpu *Mos6502) GetProgramCounter() uint16

GetProgramCounter returns the current value of the Program Counter.

func (*Mos6502) GetStackPointer

func (cpu *Mos6502) GetStackPointer() byte

GetStackPointer returns the current value of the Stack Pointer.

func (*Mos6502) GetStatusFlag

func (cpu *Mos6502) GetStatusFlag(f Flag) byte

GetStatusFlag returns the current value of specific bit on CPU status register.

func (*Mos6502) GetX

func (cpu *Mos6502) GetX() byte

GetX returns the current value of the X Register.

func (*Mos6502) GetY

func (cpu *Mos6502) GetY() byte

GetY returns the current value of the Y Register.

func (*Mos6502) InterruptRequest

func (cpu *Mos6502) InterruptRequest()

InterruptRequest is the interrupt request signal. Requires the Interrupt Disable (I) flag to be set to 0 or else nothing happens. The currently running instruction is allowed to complete before the Interrupt Request does its thing.

func (*Mos6502) NonMaskableInterrupt

func (cpu *Mos6502) NonMaskableInterrupt()

NonMaskableInterrupt is the non-maskable interrupt request signal, which cannot be ignored. It has the same behavior as the normal Interrupt Request but reads 0xfffa to set the program counter.

func (*Mos6502) Reset

func (cpu *Mos6502) Reset()

Reset signals the cpu to reset to a known state.