Serial Class Reference

Serial interface. More...

#include <machine/serial.h>

Inheritance diagram for Serial:

Public Types
enum	ComPort {   COM1 = 0x3f8 ,   COM2 = 0x2f8 ,   COM3 = 0x3e8 ,   COM4 = 0x2e8 }
	COM-Port. More...
enum	BaudRate {   BAUD_300 = 384 ,   BAUD_600 = 192 ,   BAUD_1200 = 96 ,   BAUD_2400 = 48 ,   BAUD_4800 = 24 ,   BAUD_9600 = 12 ,   BAUD_19200 = 6 ,   BAUD_38400 = 3 ,   BAUD_57600 = 2 ,   BAUD_115200 = 1 }
	Transmission speed. More...
enum	DataBits {   DATA_5BIT = 0 ,   DATA_6BIT = 1 ,   DATA_7BIT = 2 ,   DATA_8BIT = 3 }
	Number of data bits per character.
enum	StopBits {   STOP_1BIT = 0 ,   STOP_1_5BIT = 4 ,   STOP_2BIT = 4 }
	Number of stop bits per character.
enum	Parity {   PARITY_NONE = 0 ,   PARITY_ODD = 8 ,   PARITY_EVEN = 24 ,   PARITY_MARK = 40 ,   PARITY_SPACE = 56 }
	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. More...
int	read (bool blocking=true)
	Read one byte from the serial interface. More...
int	write (char out, bool blocking=true)
	Write one byte to the serial interface. More...
bool	receiveInterrupt (bool enable)
	Activate or deactivate interrupts on data reception. More...

Protected Attributes
const ComPort	port
	Selected COM port.

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

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)

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..

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

read()

int Serial::read

(

bool

blocking = true

)

Read one byte from the serial interface.

Parameters

blocking

If set, read() blocks until one byte was read

Returns

Value read from serial interface (or -1 if non-blocking and no data ready)

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)

receiveInterrupt()

bool Serial::receiveInterrupt

(

bool

enable

)

Activate or deactivate interrupts on data reception.

Calling this function reconfigures the respective register and flushes the receive buffer.

Optional:

Implement Method.

Note

In addition to the (obvious) modification in the INTERRUPT_ENABLE_REGISTER, the bit OUT_2 must be set in the MODEM_CONTROL_REGISTER to enable interrupts.

Parameters

enable

If true, interrupts will be enabled, otherwise disabled.

Returns

Previous interrupt state.

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

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