Serial Class Reference

Serial interface. More...

#include <serial.h>

Inheritance diagram for Serial:

Public Types
enum	ComPort
	COM-Port. More...
enum	BaudRate
	Transmission speed. More...
enum	DataBits
	Number of data bits per character.
enum	StopBits
	Number of stop bits per character.
enum	Parity
	parity bit

Public Member Functions
	Serial (ComPort port=COM1, BaudRate baud_rate=BAUD_115200, DataBits data_bits=DATA_8BIT, StopBits stop_bits=STOP_1BIT, Parity parity=PARITY_NONE)
	Constructor.
int	write (char out, bool blocking=true)
	Write one byte to the serial interface.

Protected Attributes
const ComPort	port
	Selected COM port.

Private Types
enum	RegisterIndex {   RECEIVE_BUFFER_REGISTER = 0 , TRANSMIT_BUFFER_REGISTER = 0 , INTERRUPT_ENABLE_REGISTER = 1 , DIVISOR_LOW_REGISTER = 0 ,   DIVISOR_HIGH_REGISTER = 1 , INTERRUPT_IDENT_REGISTER = 2 , FIFO_CONTROL_REGISTER = 2 , LINE_CONTROL_REGISTER = 3 ,   MODEM_CONTROL_REGISTER = 4 , LINE_STATUS_REGISTER = 5 , MODEM_STATUS_REGISTER = 6 }
	register index More...
enum	RegisterMask : uint8_t { }
	Mask for the respective register. More...

Private Member Functions
char	readReg (RegisterIndex reg)
	Read value from register.
void	writeReg (RegisterIndex reg, char out)
	Write value to register.

Detailed Description

Serial interface.

This class provides a serial interface (COM1 - COM4) for communication with the outside world.

The first IBM PC used the external chip 8250 UART, whereas, in today's systems, this functionality is commonly integrated into the southbridge, but remained compatible.

See also

PC8250A Data Sheet (Registers on page 11)

PC16550D Data Sheet (Successor, for optional FIFO buffer, page 16)

Member Enumeration Documentation

BaudRate

enum Serial::BaudRate

Transmission speed.

The unit Baud describes the transmission speed in number of symbols per seconds. 1 Baud therefore equals the transmission of 1 symbol per second. The possible Baud rates are whole-number dividers of the clock frequency of 115200 Hz..

ComPort

enum Serial::ComPort

COM-Port.

The serial interface and its hardware addresses. Modern desktop PCs have, at most, a single, physical COM-port (COM1)

RegisterIndex

enum Serial::RegisterIndex

private

register index

Enumerator
RECEIVE_BUFFER_REGISTER	read only
TRANSMIT_BUFFER_REGISTER	write only
INTERRUPT_IDENT_REGISTER	read only
FIFO_CONTROL_REGISTER	write only – 16550 and newer (esp. not 8250a)
LINE_CONTROL_REGISTER	highest-order bit is DLAB (see above)

RegisterMask

enum Serial::RegisterMask : uint8_t

private

Mask for the respective register.

Enumerator
INTERRUPT_PENDING	0 means interrupt pending
ENABLE_FIFO	0 means disabled ^= conforming to 8250a

Constructor & Destructor Documentation

Serial()

Serial::Serial ( ComPort  port = COM1, BaudRate  baud_rate = BAUD_115200, DataBits  data_bits = DATA_8BIT, StopBits  stop_bits = STOP_1BIT, Parity  parity = PARITY_NONE  )

explicit

Constructor.

Creates a Serial object that encapsulates the used COM port, as well as the parameters used for the serial connection. Default values are 8N1 (8 bit, no parity bit, one stop bit) with 115200 Baud using COM1.

Member Function Documentation

readReg()

char Serial::readReg ( RegisterIndex  reg )

private

Read value from register.

Parameters

reg	Register index

Returns

The value read from register

write()

int Serial::write	(	char	out,
		bool	blocking = true
	)

Write one byte to the serial interface.

Parameters

out	Byte to be written
blocking	If set, write() blocks until the byte was written

Returns

Byte written (or -1 if writing byte failed)

writeReg()

void Serial::writeReg ( RegisterIndex  reg, char  out  )

private

Write value to register.

Parameters

reg	Register index
out	value to be written

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The documentation for this class was generated from the following files:

• machine/serial.h
• machine/serial.cc