#include "machine/pit.h"
#include "machine/ioport.h"
#include "machine/core.h"

Include dependency graph for pit.cc:

Classes
struct	PIT::Control.__unnamed62__
	I/O-port bitmap for the NMI Status and Control Register. More...

Namespaces
namespace	PIT
	Abstraction of the historical Programmable Interval Timer (PIT).

Enumerations
enum	PIT::AccessMode { PIT::LATCH_COUNT_VALUE = 0 , PIT::LOW_BYTE_ONLY = 1 , PIT::HIGH_BYTE_ONLY = 2 , PIT::LOW_AND_HIGH_BYTE = 3 }
	Access mode. More...

enum	PIT::OperatingMode { PIT::INTERRUPT_ON_TERMINAL_COUNT = 0 , PIT::PROGRAMMABLE_ONE_SHOT = 1 , PIT::RATE_GENERATOR = 2 , PIT::SQUARE_WAVE_GENERATOR = 3 , PIT::SOFTWARE_TRIGGERED_STROBE = 4 , PIT::HARDWARE_TRIGGERED_STROBE = 5 }
	Operating Mode. More...

enum	PIT::Format { PIT::BINARY = 0 , PIT::BCD = 1 }
	data format More...

Functions
static IOPort	PIT::data (0x40+CHANNEL)

bool	PIT::set (uint16_t us)
	Start timer.

uint16_t	PIT::get (void)
	Reads the current timer value.

bool	PIT::isActive (void)
	Check if the timer is running.

bool	PIT::waitForTimeout (void)
	(Active) waiting for timeout

bool	PIT::delay (uint16_t us)
	Set the timer and wait for timeout.

void	PIT::pcspeaker (uint32_t freq)
	Play a given frequency on the PC speaker.

void	PIT::disable (void)
	Deactivate the timer.

Class Documentation

◆ PIT::Control.unnamed62

struct PIT::Control.__unnamed62__

I/O-port bitmap for the NMI Status and Control Register.

Note: Over time, the meaning of the bits stored at I/O port 0x61 changed; don't get the structure confused with old documentation on the IBM PC XT platform.

Class Members
uint8_t	enable_timer_counter2: 1	If enabled, the interrupt state will be visible at status_timer_counter2.
uint8_t	enable_speaker_data: 1	If set, speaker output is equal to status_timer_counter2.
uint8_t	enable_pci_serr: 1	not important, do not modify
uint8_t	enable_nmi_iochk: 1	not important, do not modify
uint8_t	refresh_cycle_toggle: 1	not important, must be 0 on write
uint8_t	status_timer_counter2: 1	will be set on timer expiration; must be 0 on write
uint8_t	status_iochk_nmi_source: 1	not important, must be 0 on write
uint8_t	status_serr_nmi_source: 1	not important, must be 0 on write