`usart.h`¶

Universal Synchronous/Asynchronous Receiver/Transmitter (USART, or commonly serial port) support.

Contents

Types
Devices
Functions
Register Map Base Pointers
Register Bit Definitions

Types ¶

struct usart_reg_map¶: USART register map type.

struct usart_dev¶: USART device type.

Devices ¶

struct usart_dev *stm32f1::USART1¶: USART1 device.

struct usart_dev *stm32f1::USART2¶: USART2 device.

struct usart_dev *stm32f1::USART3¶: USART3 device.

struct usart_dev *stm32f1::UART4¶: UART4 device.

struct usart_dev *stm32f1::UART5¶: UART5 device.

Functions ¶

void usart_init(usart_dev *dev)¶

Initialize a serial port.

Parameters

dev -
Serial port to be initialized

void usart_set_baud_rate(usart_dev *dev, uint32 clock_speed, uint32 baud)¶

void usart_enable(usart_dev *dev)¶

Enable a serial port.

USART is enabled in single buffer transmission mode, multibuffer receiver mode, 8n1.

Serial port must have a baud rate configured to work properly.

See

usart_set_baud_rate()

Parameters

dev -
Serial port to enable.

void usart_disable(usart_dev *dev)¶

Turn off a serial port.

Parameters

dev -
Serial port to be disabled

static void usart_disable_all(void)¶: Disable all serial ports.

void usart_foreach(void(*)( usart_dev *dev) fn)

uint32 usart_rx(usart_dev *dev, uint8 *buf, uint32 len)¶

Nonblocking USART receive.

Return

Number of bytes received

Parameters

dev -
Serial port to receive bytes from
buf -
Buffer to store received bytes into
len -
Maximum number of bytes to store

uint32 usart_tx(usart_dev *dev, const uint8 *buf, uint32 len)¶

Nonblocking USART transmit.

Return

Number of bytes transmitted

Parameters

dev -
Serial port to transmit over
buf -
Buffer to transmit
len -
Maximum number of bytes to transmit

void usart_putudec(usart_dev *dev, uint32 val)¶

Transmit an unsigned integer to the specified serial port in decimal format.

This function blocks until the integer’s digits have been completely transmitted.

Parameters

dev -
Serial port to send on
val -
Number to print

static void usart_putc(usart_dev *dev, uint8 byte)¶

Transmit one character on a serial port.

This function blocks until the character has been successfully transmitted.

Parameters

dev -
Serial port to send on.
byte -
Byte to transmit.

static void usart_putstr(usart_dev *dev, const char *str)¶

Transmit a character string on a serial port.

This function blocks until str is completely transmitted.

Parameters

dev -
Serial port to send on
str -
String to send

static uint8 usart_getc(usart_dev *dev)¶

Read one character from a serial port.

It’s not safe to call this function if the serial port has no data available.

Return

byte read

See

usart_data_available()

Parameters

dev -
Serial port to read from

static uint32 usart_data_available(usart_dev *dev)¶

Return the amount of data available in a serial port’s RX buffer.

Return

Number of bytes in dev’s RX buffer.

Parameters

dev -
Serial port to check

static void usart_reset_rx(usart_dev *dev)¶

Discard the contents of a serial port’s RX buffer.

Parameters

dev -
Serial port whose buffer to empty.

Register Map Base Pointers ¶

USART1_BASE¶: USART1 register map base pointer.

USART2_BASE¶: USART2 register map base pointer.

USART3_BASE¶: USART3 register map base pointer.

UART4_BASE¶: UART4 register map base pointer.

UART5_BASE¶: UART5 register map base pointer.

Register Bit Definitions ¶

Status Register ¶

USART_SR_CTS_BIT¶: Clear to send bit.

USART_SR_LBD_BIT¶: Line break detection bit.

USART_SR_TXE_BIT¶: Transmit data register empty bit.

USART_SR_TC_BIT¶: Transmission complete bit.

USART_SR_RXNE_BIT¶: Read data register not empty bit.

USART_SR_IDLE_BIT¶: IDLE line detected bit.

USART_SR_ORE_BIT¶: Overrun error bit.

USART_SR_NE_BIT¶: Noise error bit.

USART_SR_FE_BIT¶: Framing error bit.

USART_SR_PE_BIT¶: Parity error bit.

USART_SR_CTS¶: Clear to send mask.

USART_SR_LBD¶: Line break detected mask.

USART_SR_TXE¶: Transmit data register empty mask.

USART_SR_TC¶: Transmission complete mask.

USART_SR_RXNE¶: Read data register not empty mask.

USART_SR_IDLE¶: IDLE line detected mask.

USART_SR_ORE¶: Overrun error mask.

USART_SR_NE¶: Noise error mask.

USART_SR_FE¶: Framing error mask.

USART_SR_PE¶: Parity error mask.

Data register ¶

USART_DR_DR¶: Data register data value mask.

Baud Rate Register ¶

USART_BRR_DIV_MANTISSA¶: Mantissa of USARTDIV mask.

USART_BRR_DIV_FRACTION¶: Fraction of USARTDIV mask.

Control Register 1 ¶

USART_CR1_UE_BIT¶: USART enable bit.

USART_CR1_M_BIT¶: Word length bit.

USART_CR1_WAKE_BIT¶: Wakeup method bit.

USART_CR1_PCE_BIT¶: Parity control enable bit.

USART_CR1_PS_BIT¶: Parity selection bit.

USART_CR1_PEIE_BIT¶: Parity error interrupt enable bit.

USART_CR1_TXEIE_BIT¶: Transmit data regsiter not empty interrupt enable bit.

USART_CR1_TCIE_BIT¶: Transmission complete interrupt enable bit.

USART_CR1_RXNEIE_BIT¶: RXNE interrupt enable bit.

USART_CR1_IDLEIE_BIT¶: IDLE interrupt enable bit.

USART_CR1_TE_BIT¶: Transmitter enable bit.

USART_CR1_RE_BIT¶: Receiver enable bit.

USART_CR1_RWU_BIT¶: Receiver wakeup bit.

USART_CR1_SBK_BIT¶: Send break bit.

USART_CR1_UE¶: USART enable mask.

USART_CR1_M¶: Word length mask.

USART_CR1_WAKE¶: Wakeup method mask.

USART_CR1_WAKE_IDLE¶: Wakeup on idle line.

USART_CR1_WAKE_ADDR¶: Wakeup on address mark.

USART_CR1_PCE¶: Parity control enable mask.

USART_CR1_PS¶: Parity selection mask.

USART_CR1_PS_EVEN¶: Parity selection: even parity.

USART_CR1_PS_ODD¶: Parity selection: odd parity.

USART_CR1_PEIE¶: Parity error interrupt enable mask.

USART_CR1_TXEIE¶: Transmit data register empty interrupt enable mask.

USART_CR1_TCIE¶: Transmission complete interrupt enable mask.

USART_CR1_RXNEIE¶: RXNE interrupt enable mask.

USART_CR1_IDLEIE¶: IDLE line interrupt enable mask.

USART_CR1_TE¶: Transmitter enable mask.

USART_CR1_RE¶: Receiver enable mask.

USART_CR1_RWU¶: Receiver wakeup mask.

USART_CR1_RWU_ACTIVE¶: Receiver wakeup: receiver in active mode.

USART_CR1_RWU_MUTE¶: Receiver wakeup: receiver in mute mode.

USART_CR1_SBK¶: Send break.

Control Register 2 ¶

USART_CR2_LINEN_BIT¶: LIN mode enable bit.

USART_CR2_CLKEN_BIT¶: Clock enable bit.

USART_CR2_CPOL_BIT¶: Clock polarity bit.

USART_CR2_CPHA_BIT¶: Clock phase bit.

USART_CR2_LBCL_BIT¶: Last bit clock pulse bit.

USART_CR2_LBDIE_BIT¶: LIN break detection interrupt enable bit.

USART_CR2_LBDL_BIT¶: LIN break detection length bit.

USART_CR2_LINEN¶: LIN mode enable mask.

USART_CR2_STOP¶: STOP bits mask.

USART_CR2_STOP_BITS_1¶: STOP bits: 1 stop bit.

USART_CR2_STOP_BITS_POINT_5¶: STOP bits: 0.5 stop bits Not available on UART4, UART5.

USART_CR2_STOP_BITS_1_POINT_5¶: STOP bits: 1.5 stop bits Not available on UART4, UART5.

USART_CR2_STOP_BITS_2¶: STOP bits: 2 stop bits.

USART_CR2_CLKEN¶

Clock enable.

Not available on UART4, UART5

USART_CR2_CPOL¶

Clock polarity mask.

Not available on UART4, UART5

USART_CR2_CPOL_LOW¶: Clock polarity: low.

USART_CR2_CPOL_HIGH¶: Clock polarity: high.

USART_CR2_CPHA¶

Clock phase mask.

Not available on UART4, UART5

USART_CR2_CPHA_FIRST¶: Clock phase: first First clock transition is the first data capture edge.

USART_CR2_CPHA_SECOND¶: Clock phase: second Second clock transition is the first data capture edge.

USART_CR2_LBCL¶

Last bit clock pulse mask.

When set, the last bit transmitted causes a clock pulse in synchronous mode.

Not available on UART4, UART5

USART_CR2_LBDIE¶: LIN break detection interrupt enable mask.

USART_CR2_LBDL¶: LIN break detection length.

USART_CR2_LBDL_10_BIT¶: LIN break detection length: 10 bits.

USART_CR2_LBDL_11_BIT¶: LIN break detection length: 11 bits.

USART_CR2_ADD¶: Address of the USART node This is useful during multiprocessor communication.

Control Register 3 ¶

USART_CR3_CTSIE_BIT¶: Clear to send interrupt enable bit.

USART_CR3_CTSE_BIT¶: Clear to send enable bit.

USART_CR3_RTSE_BIT¶: Ready to send enable bit.

USART_CR3_DMAT_BIT¶: DMA enable transmitter bit.

USART_CR3_DMAR_BIT¶: DMA enable receiver bit.

USART_CR3_SCEN_BIT¶: Smartcard mode enable bit.

USART_CR3_NACK_BIT¶: Smartcard NACK enable bit.

USART_CR3_HDSEL_BIT¶: Half-duplex selection bit.

USART_CR3_IRLP_BIT¶: IrDA low power bit.

USART_CR3_IREN_BIT¶: IrDA mode enable bit.

USART_CR3_EIE_BIT¶: Error interrupt enable bit.

USART_CR3_CTSIE¶: Clear to send interrupt enable Not available on UART4, UART5.

USART_CR3_CTSE¶: Clear to send enable Not available on UART4, UART5.

USART_CR3_RTSE¶: Ready to send enable Not available on UART4, UART5.

USART_CR3_DMAT¶: DMA enable transmitter Not available on UART5.

USART_CR3_DMAR¶: DMA enable receiver Not available on UART5.

USART_CR3_SCEN¶: Smartcard mode enable Not available on UART4, UART5.

USART_CR3_NACK¶: Smartcard NACK enable Not available on UART4, UART5.

USART_CR3_HDSEL¶: Half-duplex selection When set, single-wire half duplex mode is selected.

USART_CR3_IRLP¶: IrDA low power mode.

USART_CR3_IRLP_NORMAL¶: IrDA mode: normal.

USART_CR3_IRLP_LOW_POWER¶: IrDA mode: low power.

USART_CR3_IREN¶: IrDA mode enable.

USART_CR3_EIE¶: Error interrupt enable.

Guard Time and Prescaler Register ¶

USART_GTPR_GT¶

Guard time value mask Used in Smartcard mode.

Not available on UART4, UART5.

USART_GTPR_PSC¶

Prescaler value mask Restrictions on this value apply, depending on the USART mode.

Not available on UART4, UART5.

librambutan prerelease documentation

`usart.h`¶

Types ¶

Devices ¶

Functions ¶

Register Map Base Pointers ¶

Register Bit Definitions ¶

Status Register ¶

Data register ¶

Baud Rate Register ¶

Control Register 1 ¶

Control Register 2 ¶

Control Register 3 ¶

Guard Time and Prescaler Register ¶

Table Of Contents

Project Resources

usart.h¶

`usart.h`¶