File syn_uart.h¶

FileList > drivers > syn_uart.h

UART driver — buffered I/O and formatted output. More...

#include "../common/syn_defs.h"
#include "../port/syn_port_uart.h"
#include "../util/syn_ringbuf.h"

Classes¶

Type	Name
struct	SYN_UART UART driver handle.
struct	SYN_UART_Config Configuration struct for UART initialization with optional DMA.

Public Functions¶

Type	Name
SYN_Status	syn_uart_deinit (SYN_UART * uart) De-initialize a UART instance.
SYN_Status	syn_uart_init (SYN_UART * uart, SYN_UARTInstance instance, uint32_t baudrate) Initialize a UART instance with buffered I/O.
SYN_Status	syn_uart_init_config (SYN_UART * uart, const SYN_UART_Config * cfg) Initialize a UART instance with custom configuration (optional DMA).
size_t	syn_uart_read (SYN_UART * uart, uint8_t * data, size_t max_len) Read bytes from the UART RX ring buffer.
bool	syn_uart_rx_isr_feed (SYN_UART * uart, uint8_t byte) Feed a received byte into the UART RX ring buffer.
bool	syn_uart_tx_complete (const SYN_UART * uart) Check if asynchronous TX is complete (tx_rb drained AND hardware shift register clear).
bool	syn_uart_tx_isr_flush (SYN_UART * uart) TX ISR drain callback — call from UART TXE interrupt.
SYN_Status	syn_uart_write (const SYN_UART * uart, const uint8_t * data, size_t len, uint32_t timeout_ms) Write a buffer of bytes to the UART (blocking).
SYN_Status	syn_uart_write_async (SYN_UART * uart, const uint8_t * data, size_t len) Non-blocking write to UART TX ring buffer (all-or-nothing atomic).
SYN_Status	syn_uart_write_str (const SYN_UART * uart, const char * str, uint32_t timeout_ms) Write a string to the UART (blocking).

Macros¶

Type	Name
define	SYN_UART_MAX_INSTANCES `2` Maximum UART instances supported.
define	SYN_UART_RX_BUF_SIZE `128` UART receive buffer size (bytes).
define	SYN_UART_TX_BUF_SIZE `128` UART transmit buffer size (bytes).

Detailed Description¶

Provides interrupt-driven buffered UART on top of the port layer. Each UART instance gets a TX and RX ring buffer. The buffer sizes are configurable in syn_config.h.

Public Functions Documentation¶

function syn_uart_deinit¶

De-initialize a UART instance.

SYN_Status syn_uart_deinit (
    SYN_UART * uart
)

Parameters:

uart UART handle to deinitialize.

Returns:

SYN_OK on success.

function syn_uart_init¶

Initialize a UART instance with buffered I/O.

SYN_Status syn_uart_init (
    SYN_UART * uart,
    SYN_UARTInstance instance,
    uint32_t baudrate
)

Parameters:

uart Pointer to a caller-owned SYN_UART struct.
instance UART peripheral number (0, 1, …).
baudrate Desired baud rate.

Returns:

SYN_OK on success.

function syn_uart_init_config¶

Initialize a UART instance with custom configuration (optional DMA).

SYN_Status syn_uart_init_config (
    SYN_UART * uart,
    const SYN_UART_Config * cfg
)

Parameters:

uart Pointer to a caller-owned SYN_UART struct.
cfg Pointer to initialization configuration.

Returns:

SYN_OK on success.

function syn_uart_read¶

Read bytes from the UART RX ring buffer.

size_t syn_uart_read (
    SYN_UART * uart,
    uint8_t * data,
    size_t max_len
)

Reads up to max_len bytes that have been received. Non-blocking: returns immediately with however many bytes are available.

Parameters:

uart UART handle.
data Buffer to read into.
max_len Maximum number of bytes to read.

Returns:

Number of bytes actually read.

function syn_uart_rx_isr_feed¶

Feed a received byte into the UART RX ring buffer.

bool syn_uart_rx_isr_feed (
    SYN_UART * uart,
    uint8_t byte
)

Call this from your UART RX ISR to push incoming data into the driver's buffer.

Parameters:

uart UART handle.
byte The received byte.

Returns:

true if the byte was stored, false if the RX buffer is full.

function syn_uart_tx_complete¶

Check if asynchronous TX is complete (tx_rb drained AND hardware shift register clear).

bool syn_uart_tx_complete (
    const SYN_UART * uart
)

Parameters:

uart UART handle.

Returns:

true if no bytes remain in software tx_rb AND hardware TC flag is set.

function syn_uart_tx_isr_flush¶

TX ISR drain callback — call from UART TXE interrupt.

bool syn_uart_tx_isr_flush (
    SYN_UART * uart
)

Pops the next byte from tx_rb into the hardware data register. When the ring buffer empties, disables the TXE interrupt.

Parameters:

uart UART handle.

Returns:

true if a byte was transmitted, false if tx_rb is empty.

function syn_uart_write¶

Write a buffer of bytes to the UART (blocking).

SYN_Status syn_uart_write (
    const SYN_UART * uart,
    const uint8_t * data,
    size_t len,
    uint32_t timeout_ms
)

Parameters:

uart UART handle.
data Data to transmit.
len Number of bytes.
timeout_ms Timeout in milliseconds (0 = no timeout).

Returns:

SYN_OK on success.

function syn_uart_write_async¶

Non-blocking write to UART TX ring buffer (all-or-nothing atomic).

SYN_Status syn_uart_write_async (
    SYN_UART * uart,
    const uint8_t * data,
    size_t len
)

Pushes data into the internal TX ring buffer if space is available for all len bytes, and enables the TX interrupt to drain asynchronously. Returns SYN_BUSY without modifying the buffer if space is insufficient.

Parameters:

uart UART handle.
data Data to transmit.
len Number of bytes.

Returns:

SYN_OK on success, SYN_BUSY if ring buffer free space < len.

function syn_uart_write_str¶

Write a string to the UART (blocking).

SYN_Status syn_uart_write_str (
    const SYN_UART * uart,
    const char * str,
    uint32_t timeout_ms
)

Parameters:

uart UART handle.
str Null-terminated string.
timeout_ms Timeout in milliseconds (0 = no timeout).

Returns:

SYN_OK on success.

Macro Definition Documentation¶

define SYN_UART_MAX_INSTANCES¶

Maximum UART instances supported.

#define SYN_UART_MAX_INSTANCES `2`

define SYN_UART_RX_BUF_SIZE¶

UART receive buffer size (bytes).

#define SYN_UART_RX_BUF_SIZE `128`

define SYN_UART_TX_BUF_SIZE¶

UART transmit buffer size (bytes).

#define SYN_UART_TX_BUF_SIZE `128`

The documentation for this class was generated from the following file src/syntropic/drivers/syn_uart.h