callfn

Documentation

Overview

Package Callfn facilitates the ARM CALLFN process common to both DPC+ and CDF* cartridge mappers. It does not handle the ARM itself and cartridge mappers that use it should take care in particular to Run() and Step() the ARM when required.

Index

• type CallFn
  • func (cf *CallFn) Check(addr uint16) (uint8, bool)
  • func (cf *CallFn) IsActive() bool
  • func (cf *CallFn) Start(cycles float32)
  • func (cf *CallFn) Step(immediate bool, vcsClock float32) bool

Types

type CallFn

type CallFn struct {

	// on ARM program conclusion we JMP to the address after the CALLFN
	ResumeAddr uint16
	// contains filtered or unexported fields
}

CallFn keeps track of the CallFn process common to both DPC+ and CDF* cartridge mappers.

func (*CallFn) Check

func (cf *CallFn) Check(addr uint16) (uint8, bool)

Check state of CallFn. Returns true if it is active and false if it is not. If CallFn is active then the the value to put on the data bus is also returned. If CallFn is not active then the data bus value should be determined in the normal way (most probably by reading the cartridge ROM).

func (*CallFn) IsActive

func (cf *CallFn) IsActive() bool

IsActive returns true if ARM program is still running.

func (*CallFn) Start

func (cf *CallFn) Start(cycles float32)

Start the CallFn process.

func (*CallFn) Step

func (cf *CallFn) Step(immediate bool, vcsClock float32) bool

Step forward one clock. Returns true if the ARM program is running and false otherwise.