#include <ZeroRAMBank.h>

Inheritance diagram for libsidplayfp::ZeroRAMBank:

Collaboration diagram for libsidplayfp::ZeroRAMBank:

Public Member Functions
	ZeroRAMBank (PLA &pla, SystemRAMBank &ramBank)

void	reset ()

uint8_t	peek (uint_least16_t address) override

void	poke (uint_least16_t address, uint8_t value) override

Detailed Description

Area backed by RAM, including cpu port addresses 0 and 1.

This is bit of a fake. We know that the CPU port is an internal detail of the CPU, and therefore CPU should simply pay the price for reading/writing to $00/$01.

However, that would slow down all accesses, which is suboptimal. Therefore we install this little hook to the 4k 0 region to deal with this.

Implementation based on VICE code.

Member Function Documentation

◆ peek()

uint8_t libsidplayfp::ZeroRAMBank::peek ( uint_least16_t address )

inlineoverridevirtual

Bank read. You probably should override this method, except if the Bank is only used in write context.

Parameters

address value to read from

Returns: value at address

Implements libsidplayfp::Bank.

◆ poke()

void libsidplayfp::ZeroRAMBank::poke	(	uint_least16_t	address,
		uint8_t	value
	)

inlineoverridevirtual

Bank write.

Override this method if you expect write operations on your bank. Leave unimplemented if it's logically/operationally impossible for writes to ever arrive to bank.