Uart16550< RegisterType > Class Template Reference

Generic 16550A memory-mapped register layout. More...

#include <platform-uart.hh>

Public Member Functions
bool	can_write () volatile
	Returns true if the transmit buffer is empty.
bool	can_read () volatile
	Returns true if the receive buffer is not.
uint8_t	blocking_read () volatile
	Read one byte, blocking until a byte is available.
void	blocking_write (uint8_t byte) volatile
	Write one byte, blocking until the byte is written.
template<typename T = decltype(no_custom_init)>
void	init (int divisor=1, T &&otherSetup=no_custom_init) volatile
	Initialise the UART.

Public Attributes
RegisterType	data
	The interface to the read/write FIFOs for this UART.
RegisterType	intrEnable
	Interrupt-enabled control / status.
RegisterType	intrIDandFifo
	Interrupt identification and FIFO enable/disable.
RegisterType	lineControl
	Specifies properties of the line (stop bit, parity, and so on).
RegisterType	modemControl
	Modem control.
const RegisterType	LineStatus
	The line status word.
const RegisterType	ModemStatus
	Modem status.
RegisterType	scratch
	Scratch register.

Detailed Description

template<typename RegisterType = uint32_t>
class Uart16550< RegisterType >

Generic 16550A memory-mapped register layout.

The registers are 8 bits wide, but typically the bus supports only 4-byte (or larger) transactions and so they are padded to a 32-bit word. The template parameter allows this to be controlled.

Definition at line 17 of file platform-uart.hh.

Member Function Documentation

blocking_read()

template<typename RegisterType = uint32_t>

uint8_t Uart16550< RegisterType >::blocking_read ( ) volatile

inline

Read one byte, blocking until a byte is available.

Definition at line 99 of file platform-uart.hh.

blocking_write()

template<typename RegisterType = uint32_t>

void Uart16550< RegisterType >::blocking_write ( uint8_t byte ) volatile

inline

Write one byte, blocking until the byte is written.

Definition at line 110 of file platform-uart.hh.

can_read()

template<typename RegisterType = uint32_t>

bool Uart16550< RegisterType >::can_read ( ) volatile

inline

Returns true if the receive buffer is not.

Definition at line 91 of file platform-uart.hh.

Referenced by Uart16550< uint32_t >::blocking_read().

can_write()

template<typename RegisterType = uint32_t>

bool Uart16550< RegisterType >::can_write ( ) volatile

inline

Returns true if the transmit buffer is empty.

Definition at line 77 of file platform-uart.hh.

Referenced by Uart16550< uint32_t >::blocking_write().

init()

template<typename RegisterType = uint32_t>

template<typename T = decltype(no_custom_init)>

void Uart16550< RegisterType >::init ( int divisor = 1, T && otherSetup = no_custom_init ) volatile

inline

Initialise the UART.

Definition at line 122 of file platform-uart.hh.

Referenced by SynopsisExtended16550< DefaultBaudRate >::init().

Member Data Documentation

data

template<typename RegisterType = uint32_t>

RegisterType Uart16550< RegisterType >::data

The interface to the read/write FIFOs for this UART.

This is also the low byte of the divisor when the divisor latch (bit 7 of the lineControl) is set.

Definition at line 28 of file platform-uart.hh.

intrEnable

template<typename RegisterType = uint32_t>

RegisterType Uart16550< RegisterType >::intrEnable

Interrupt-enabled control / status.

Write 1 to enabled, 0 to disable, to each of the low four bits:

0: Data-receive interrupt 1: Transmit holding register empty interrupt 2: Receive line status interrupts 3: Modem status interrupts.

When bit 7 of lineControl is set, this is instead the divisor-latch-high register and stores the high 8 bits of the divisor.

Definition at line 41 of file platform-uart.hh.

intrIDandFifo

template<typename RegisterType = uint32_t>

RegisterType Uart16550< RegisterType >::intrIDandFifo

Interrupt identification and FIFO enable/disable.

We only care about the low bit here, which enables the FIFO.

Definition at line 47 of file platform-uart.hh.

lineControl

template<typename RegisterType = uint32_t>

RegisterType Uart16550< RegisterType >::lineControl

Specifies properties of the line (stop bit, parity, and so on).

The only bit that we use is bit 7, the divisor latch, which enables writing the speed.

Definition at line 53 of file platform-uart.hh.

LineStatus

template<typename RegisterType = uint32_t>

const RegisterType Uart16550< RegisterType >::LineStatus

The line status word.

The bits that we care about are:

0: Receive ready 5: Transmit buffer empty

Definition at line 64 of file platform-uart.hh.

modemControl

template<typename RegisterType = uint32_t>

RegisterType Uart16550< RegisterType >::modemControl

Modem control.

Definition at line 57 of file platform-uart.hh.

ModemStatus

template<typename RegisterType = uint32_t>

const RegisterType Uart16550< RegisterType >::ModemStatus

Modem status.

Definition at line 68 of file platform-uart.hh.

scratch

template<typename RegisterType = uint32_t>

RegisterType Uart16550< RegisterType >::scratch

Scratch register.

Unused.

Definition at line 72 of file platform-uart.hh.

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

• sdk/include/platform/generic-riscv/platform-uart.hh