AM243x MCU+ SDK  09.02.00

Introduction

This module contains APIs to program and use the UART.

Files

file  uart/v0/uart.h
 This file contains the prototype of UART driver APIs.
 

Data Structures

struct  UART_Params
 UART Parameters. More...
 
struct  UART_Attrs
 UART instance attributes - used during init time. More...
 
struct  UART_Object
 UART driver object. More...
 
struct  UART_Config
 UART global configuration array. More...
 

Functions

void UART_init (void)
 This function initializes the UART module. More...
 
void UART_deinit (void)
 This function de-initializes the UART module. More...
 
UART_Handle UART_open (uint32_t index, const UART_Params *prms)
 This function opens a given UART peripheral. More...
 
void UART_close (UART_Handle handle)
 Function to close a UART peripheral specified by the UART handle. More...
 
int32_t UART_write (UART_Handle handle, UART_Transaction *trans)
 Function to perform UART write operation. More...
 
int32_t UART_read (UART_Handle handle, UART_Transaction *trans)
 Function to perform UART read operation. More...
 
int32_t UART_writeCancel (UART_Handle handle, UART_Transaction *trans)
 Function to perform UART canceling of current write transaction. More...
 
int32_t UART_readCancel (UART_Handle handle, UART_Transaction *trans)
 Function to perform UART canceling of current read transaction. More...
 
UART_Handle UART_getHandle (uint32_t index)
 Function to return a open'ed UART handle given a UART instance index. More...
 
void UART_flushTxFifo (UART_Handle handle)
 Function to flush a TX FIFO of peripheral specified by the UART handle. More...
 
uint32_t UART_getBaseAddr (UART_Handle handle)
 Function to get base address of UART instance of a particular handle. More...
 
void UART_Transaction_init (UART_Transaction *trans)
 Function to initialize the UART_Transaction struct to its defaults. More...
 
void UART_Params_init (UART_Params *prms)
 Function to initialize the UART_Params struct to its defaults. More...
 

Typedefs

typedef void * UART_Handle
 A handle that is returned from a UART_open() call. More...
 
typedef void(* UART_CallbackFxn) (UART_Handle handle, UART_Transaction *transaction)
 The definition of a callback function used by the UART driver when used in UART_TRANSFER_MODE_CALLBACK. More...
 

Transfer Mode

This determines whether the driver operates synchronously or asynchronously

In UART_TRANSFER_MODE_BLOCKING mode UART_read() and UART_write() blocks code execution until the transaction has completed

In UART_TRANSFER_MODE_CALLBACK UART_read() and UART_write() does not block code execution and instead calls a UART_CallbackFxn callback function when the transaction has completed

#define UART_TRANSFER_MODE_BLOCKING   (0U)
 UART read/write APIs blocks execution. This mode can only be used when called within a Task context. More...
 
#define UART_TRANSFER_MODE_CALLBACK   (1U)
 UART read/write APIs does not block code execution and will call a UART_CallbackFxn. This mode can be used in a Task, Swi, or Hwi context. More...
 

Macro Definition Documentation

◆ UART_TRANSFER_MODE_BLOCKING

#define UART_TRANSFER_MODE_BLOCKING   (0U)

UART read/write APIs blocks execution. This mode can only be used when called within a Task context.

◆ UART_TRANSFER_MODE_CALLBACK

#define UART_TRANSFER_MODE_CALLBACK   (1U)

UART read/write APIs does not block code execution and will call a UART_CallbackFxn. This mode can be used in a Task, Swi, or Hwi context.

Typedef Documentation

◆ UART_Handle

typedef void* UART_Handle

A handle that is returned from a UART_open() call.

◆ UART_CallbackFxn

typedef void(* UART_CallbackFxn) (UART_Handle handle, UART_Transaction *transaction)

The definition of a callback function used by the UART driver when used in UART_TRANSFER_MODE_CALLBACK.

Parameters
handleUART_Handle
transaction*Pointer to a UART_Transaction

Function Documentation

◆ UART_init()

void UART_init ( void  )

This function initializes the UART module.

◆ UART_deinit()

void UART_deinit ( void  )

This function de-initializes the UART module.

◆ UART_open()

UART_Handle UART_open ( uint32_t  index,
const UART_Params prms 
)

This function opens a given UART peripheral.

Precondition
UART controller has been initialized using UART_init()
Parameters
indexIndex of config to use in the UART_Config array
prmsPointer to open parameters. If NULL is passed, then default values will be used
Returns
A UART_Handle on success or a NULL on an error or if it has been opened already
See also
UART_init()
UART_close()
UART_Params_init

◆ UART_close()

void UART_close ( UART_Handle  handle)

Function to close a UART peripheral specified by the UART handle.

Precondition
UART_open() has to be called first
Parameters
handleUART_Handle returned from UART_open()
See also
UART_open()

◆ UART_write()

int32_t UART_write ( UART_Handle  handle,
UART_Transaction trans 
)

Function to perform UART write operation.

In UART_TRANSFER_MODE_BLOCKING, UART_write() will block task execution until the transaction has completed or a timeout has occurred.

In UART_TRANSFER_MODE_CALLBACK, UART_write() does not block task execution, but calls a UART_CallbackFxn once the transfer has finished. This makes UART_write() safe to be used within a Task, software or hardware interrupt context.

In interrupt mode, UART_write() does not wait until tx fifo is empty. Application needs to call UART_flushTxFifo() to ensure write is completed. i.e. data is out from the FIFO and shift registers.

From calling UART_write() until transfer completion, the UART_Transaction structure must stay persistent and must not be altered by application code. It is also forbidden to modify the content of the UART_Transaction.buf during a transaction, even though the physical transfer might not have started yet. Doing this can result in data corruption.

Parameters
handleUART_Handle returned from UART_open()
transPointer to a UART_Transaction. All of the fields within transaction except UART_Transaction.count and UART_Transaction.status are WO (write-only) unless otherwise noted in the driver implementations. If a transaction timeout has occurred, UART_Transaction.count will contain the number of bytes that were transferred. Neither is it allowed to modify the transaction object nor the content of UART_Transaction.buf until the transfer has completed
Returns
SystemP_SUCCESS if started successfully; else error on failure
See also
UART_open

◆ UART_read()

int32_t UART_read ( UART_Handle  handle,
UART_Transaction trans 
)

Function to perform UART read operation.

In UART_TRANSFER_MODE_BLOCKING, UART_read() will block task execution until the transaction has completed or a timeout has occurred.

In UART_TRANSFER_MODE_CALLBACK, UART_read() does not block task execution, but calls a UART_CallbackFxn once the transfer has finished. This makes UART_read() safe to be used within a Task, software or hardware interrupt context.

From calling UART_read() until transfer completion, the UART_Transaction structure must stay persistent and must not be altered by application code. It is also forbidden to modify the content of the UART_Transaction.buf during a transaction, even though the physical transfer might not have started yet. Doing this can result in data corruption.

Parameters
handleUART_Handle returned from UART_open()
transPointer to a UART_Transaction. All of the fields within transaction except UART_Transaction.count and UART_Transaction.status are WO (write-only) unless otherwise noted in the driver implementations. If a transaction timeout has occurred, UART_Transaction.count will contain the number of bytes that were transferred. Neither is it allowed to modify the transaction object nor the content of UART_Transaction.buf until the transfer has completed
Returns
SystemP_SUCCESS if started successfully; else error on failure
See also
UART_open

◆ UART_writeCancel()

int32_t UART_writeCancel ( UART_Handle  handle,
UART_Transaction trans 
)

Function to perform UART canceling of current write transaction.

In UART_TRANSFER_MODE_CALLBACK, UART_writeCancel() does not block task execution, but calls a UART_CallbackFxn once the cancel has finished. This makes UART_writeCancel() safe to be used within a Task, software or hardware interrupt context.

From calling UART_writeCancel() until cancel completion, the UART_Transaction structure must stay persistent and must not be altered by application code. It is also forbidden to modify the content of the UART_Transaction.buf during a transaction, even though the physical transfer might not have started yet. Doing this can result in data corruption.

Parameters
handleUART_Handle returned from UART_open()
transPointer to a UART_Transaction. All of the fields within transaction except UART_Transaction.count and UART_Transaction.status are WO (write-only) unless otherwise noted in the driver implementations. If a transaction timeout has occurred, UART_Transaction.count will contain the number of bytes that were transferred. Neither is it allowed to modify the transaction object nor the content of UART_Transaction.buf until the transfer has completed
Returns
SystemP_SUCCESS if started successfully; else error on failure
See also
UART_open

◆ UART_readCancel()

int32_t UART_readCancel ( UART_Handle  handle,
UART_Transaction trans 
)

Function to perform UART canceling of current read transaction.

In UART_TRANSFER_MODE_CALLBACK, UART_readCancel() does not block task execution, but calls a UART_CallbackFxn once the cancel has finished. This makes UART_writeCancel() safe to be used within a Task, software or hardware interrupt context.

From calling UART_readCancel() until cancel completion, the UART_Transaction structure must stay persistent and must not be altered by application code. It is also forbidden to modify the content of the UART_Transaction.buf during a transaction, even though the physical transfer might not have started yet. Doing this can result in data corruption.

Parameters
handleUART_Handle returned from UART_open()
transPointer to a UART_Transaction. All of the fields within transaction except UART_Transaction.count and UART_Transaction.status are WO (write-only) unless otherwise noted in the driver implementations. If a transaction timeout has occurred, UART_Transaction.count will contain the number of bytes that were transferred. Neither is it allowed to modify the transaction object nor the content of UART_Transaction.buf until the transfer has completed
Returns
SystemP_SUCCESS if started successfully; else error on failure
See also
UART_open

◆ UART_getHandle()

UART_Handle UART_getHandle ( uint32_t  index)

Function to return a open'ed UART handle given a UART instance index.

Parameters
indexIndex of config to use in the UART_Config array
Returns
A UART_Handle on success or a NULL on an error or if the instance index has NOT been opened yet

◆ UART_flushTxFifo()

void UART_flushTxFifo ( UART_Handle  handle)

Function to flush a TX FIFO of peripheral specified by the UART handle.

Precondition
UART_open() has to be called first
Parameters
handleUART_Handle returned from UART_open()
See also
UART_open()

◆ UART_getBaseAddr()

uint32_t UART_getBaseAddr ( UART_Handle  handle)

Function to get base address of UART instance of a particular handle.

Parameters
handleUART_Handle returned from UART_open()
See also
UART_open

◆ UART_Transaction_init()

void UART_Transaction_init ( UART_Transaction trans)

Function to initialize the UART_Transaction struct to its defaults.

Parameters
transPointer to UART_Transaction structure for initialization

◆ UART_Params_init()

void UART_Params_init ( UART_Params prms)

Function to initialize the UART_Params struct to its defaults.

Parameters
prmsPointer to UART_Params structure for initialization

Variable Documentation

◆ gUartConfig

UART_Config gUartConfig[]
extern

Externally defined driver configuration array.

◆ gUartConfigNum

uint32_t gUartConfigNum
extern

Externally defined driver configuration array size.