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stm32f4xx_usart.c
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stm32f4xx_usart.c
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/**
******************************************************************************
* @file stm32f4xx_usart.c
* @author MCD Application Team
* @version V1.0.2
* @date 05-March-2012
* @brief This file provides firmware functions to manage the following
* functionalities of the Universal synchronous asynchronous receiver
* transmitter (USART):
* - Initialization and Configuration
* - Data transfers
* - Multi-Processor Communication
* - LIN mode
* - Half-duplex mode
* - Smartcard mode
* - IrDA mode
* - DMA transfers management
* - Interrupts and flags management
*
* @verbatim
*
* ===================================================================
* How to use this driver
* ===================================================================
* 1. Enable peripheral clock using the follwoing functions
* RCC_APB2PeriphClockCmd(RCC_APB2Periph_USARTx, ENABLE) for USART1 and USART6
* RCC_APB1PeriphClockCmd(RCC_APB1Periph_USARTx, ENABLE) for USART2, USART3, UART4 or UART5.
*
* 2. According to the USART mode, enable the GPIO clocks using
* RCC_AHB1PeriphClockCmd() function. (The I/O can be TX, RX, CTS,
* or/and SCLK).
*
* 3. Peripheral's alternate function:
* - Connect the pin to the desired peripherals' Alternate
* Function (AF) using GPIO_PinAFConfig() function
* - Configure the desired pin in alternate function by:
* GPIO_InitStruct->GPIO_Mode = GPIO_Mode_AF
* - Select the type, pull-up/pull-down and output speed via
* GPIO_PuPd, GPIO_OType and GPIO_Speed members
* - Call GPIO_Init() function
*
* 4. Program the Baud Rate, Word Length , Stop Bit, Parity, Hardware
* flow control and Mode(Receiver/Transmitter) using the USART_Init()
* function.
*
* 5. For synchronous mode, enable the clock and program the polarity,
* phase and last bit using the USART_ClockInit() function.
*
* 5. Enable the NVIC and the corresponding interrupt using the function
* USART_ITConfig() if you need to use interrupt mode.
*
* 6. When using the DMA mode
* - Configure the DMA using DMA_Init() function
* - Active the needed channel Request using USART_DMACmd() function
*
* 7. Enable the USART using the USART_Cmd() function.
*
* 8. Enable the DMA using the DMA_Cmd() function, when using DMA mode.
*
* Refer to Multi-Processor, LIN, half-duplex, Smartcard, IrDA sub-sections
* for more details
*
* In order to reach higher communication baudrates, it is possible to
* enable the oversampling by 8 mode using the function USART_OverSampling8Cmd().
* This function should be called after enabling the USART clock (RCC_APBxPeriphClockCmd())
* and before calling the function USART_Init().
*
* @endverbatim
*
******************************************************************************
* @attention
*
* <h2><center>© COPYRIGHT 2012 STMicroelectronics</center></h2>
*
* Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
* You may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.st.com/software_license_agreement_liberty_v2
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
******************************************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include "stm32f4xx_usart.h"
#include "stm32f4xx_rcc.h"
/** @addtogroup STM32F4xx_StdPeriph_Driver
* @{
*/
/** @defgroup USART
* @brief USART driver modules
* @{
*/
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/*!< USART CR1 register clear Mask ((~(uint16_t)0xE9F3)) */
#define CR1_CLEAR_MASK_USART ((uint16_t)(USART_CR1_M | USART_CR1_PCE | \
USART_CR1_PS | USART_CR1_TE | \
USART_CR1_RE))
/*!< USART CR2 register clock bits clear Mask ((~(uint16_t)0xF0FF)) */
#define CR2_CLOCK_CLEAR_MASK ((uint16_t)(USART_CR2_CLKEN | USART_CR2_CPOL | \
USART_CR2_CPHA | USART_CR2_LBCL))
/*!< USART CR3 register clear Mask ((~(uint16_t)0xFCFF)) */
#define CR3_CLEAR_MASK ((uint16_t)(USART_CR3_RTSE | USART_CR3_CTSE))
/*!< USART Interrupts mask */
#define IT_MASK ((uint16_t)0x001F)
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
/** @defgroup USART_Private_Functions
* @{
*/
/** @defgroup USART_Group1 Initialization and Configuration functions
* @brief Initialization and Configuration functions
*
@verbatim
===============================================================================
Initialization and Configuration functions
===============================================================================
This subsection provides a set of functions allowing to initialize the USART
in asynchronous and in synchronous modes.
- For the asynchronous mode only these parameters can be configured:
- Baud Rate
- Word Length
- Stop Bit
- Parity: If the parity is enabled, then the MSB bit of the data written
in the data register is transmitted but is changed by the parity bit.
Depending on the frame length defined by the M bit (8-bits or 9-bits),
the possible USART frame formats are as listed in the following table:
+-------------------------------------------------------------+
| M bit | PCE bit | USART frame |
|---------------------|---------------------------------------|
| 0 | 0 | | SB | 8 bit data | STB | |
|---------|-----------|---------------------------------------|
| 0 | 1 | | SB | 7 bit data | PB | STB | |
|---------|-----------|---------------------------------------|
| 1 | 0 | | SB | 9 bit data | STB | |
|---------|-----------|---------------------------------------|
| 1 | 1 | | SB | 8 bit data | PB | STB | |
+-------------------------------------------------------------+
- Hardware flow control
- Receiver/transmitter modes
The USART_Init() function follows the USART asynchronous configuration procedure
(details for the procedure are available in reference manual (RM0090)).
- For the synchronous mode in addition to the asynchronous mode parameters these
parameters should be also configured:
- USART Clock Enabled
- USART polarity
- USART phase
- USART LastBit
These parameters can be configured using the USART_ClockInit() function.
@endverbatim
* @{
*/
/**
* @brief Deinitializes the USARTx peripheral registers to their default reset values.
* @param USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or
* UART peripheral.
* @retval None
*/
void USART_DeInit(USART_TypeDef* USARTx)
{
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
if (USARTx == USART1)
{
RCC_APB2PeriphResetCmd(RCC_APB2Periph_USART1, ENABLE);
RCC_APB2PeriphResetCmd(RCC_APB2Periph_USART1, DISABLE);
}
else if (USARTx == USART2)
{
RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART2, ENABLE);
RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART2, DISABLE);
}
else if (USARTx == USART3)
{
RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART3, ENABLE);
RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART3, DISABLE);
}
else if (USARTx == UART4)
{
RCC_APB1PeriphResetCmd(RCC_APB1Periph_UART4, ENABLE);
RCC_APB1PeriphResetCmd(RCC_APB1Periph_UART4, DISABLE);
}
else if (USARTx == UART5)
{
RCC_APB1PeriphResetCmd(RCC_APB1Periph_UART5, ENABLE);
RCC_APB1PeriphResetCmd(RCC_APB1Periph_UART5, DISABLE);
}
else
{
if (USARTx == USART6)
{
RCC_APB2PeriphResetCmd(RCC_APB2Periph_USART6, ENABLE);
RCC_APB2PeriphResetCmd(RCC_APB2Periph_USART6, DISABLE);
}
}
}
/**
* @brief Initializes the USARTx peripheral according to the specified
* parameters in the USART_InitStruct .
* @param USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or
* UART peripheral.
* @param USART_InitStruct: pointer to a USART_InitTypeDef structure that contains
* the configuration information for the specified USART peripheral.
* @retval None
*/
void USART_Init(USART_TypeDef* USARTx, USART_InitTypeDef* USART_InitStruct)
{
uint32_t tmpreg = 0x00, apbclock = 0x00;
uint32_t integerdivider = 0x00;
uint32_t fractionaldivider = 0x00;
RCC_ClocksTypeDef RCC_ClocksStatus;
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
assert_param(IS_USART_BAUDRATE(USART_InitStruct->USART_BaudRate));
assert_param(IS_USART_WORD_LENGTH(USART_InitStruct->USART_WordLength));
assert_param(IS_USART_STOPBITS(USART_InitStruct->USART_StopBits));
assert_param(IS_USART_PARITY(USART_InitStruct->USART_Parity));
assert_param(IS_USART_MODE(USART_InitStruct->USART_Mode));
assert_param(IS_USART_HARDWARE_FLOW_CONTROL(USART_InitStruct->USART_HardwareFlowControl));
/* The hardware flow control is available only for USART1, USART2, USART3 and USART6 */
if (USART_InitStruct->USART_HardwareFlowControl != USART_HardwareFlowControl_None)
{
assert_param(IS_USART_1236_PERIPH(USARTx));
}
/*---------------------------- USART CR2 Configuration -----------------------*/
tmpreg = USARTx->CR2;
/* Clear STOP[13:12] bits */
tmpreg &= (uint32_t)~((uint32_t)USART_CR2_STOP);
/* Configure the USART Stop Bits, Clock, CPOL, CPHA and LastBit :
Set STOP[13:12] bits according to USART_StopBits value */
tmpreg |= (uint32_t)USART_InitStruct->USART_StopBits;
/* Write to USART CR2 */
USARTx->CR2 = (uint16_t)tmpreg;
/*---------------------------- USART CR1 Configuration -----------------------*/
tmpreg = USARTx->CR1;
/* Clear M, PCE, PS, TE and RE bits */
tmpreg &= (uint32_t)~((uint32_t)CR1_CLEAR_MASK_USART);
/* Configure the USART Word Length, Parity and mode:
Set the M bits according to USART_WordLength value
Set PCE and PS bits according to USART_Parity value
Set TE and RE bits according to USART_Mode value */
tmpreg |= (uint32_t)USART_InitStruct->USART_WordLength | USART_InitStruct->USART_Parity |
USART_InitStruct->USART_Mode;
/* Write to USART CR1 */
USARTx->CR1 = (uint16_t)tmpreg;
/*---------------------------- USART CR3 Configuration -----------------------*/
tmpreg = USARTx->CR3;
/* Clear CTSE and RTSE bits */
tmpreg &= (uint32_t)~((uint32_t)CR3_CLEAR_MASK);
/* Configure the USART HFC :
Set CTSE and RTSE bits according to USART_HardwareFlowControl value */
tmpreg |= USART_InitStruct->USART_HardwareFlowControl;
/* Write to USART CR3 */
USARTx->CR3 = (uint16_t)tmpreg;
/*---------------------------- USART BRR Configuration -----------------------*/
/* Configure the USART Baud Rate */
RCC_GetClocksFreq(&RCC_ClocksStatus);
if ((USARTx == USART1) || (USARTx == USART6))
{
apbclock = RCC_ClocksStatus.PCLK2_Frequency;
}
else
{
apbclock = RCC_ClocksStatus.PCLK1_Frequency;
}
/* Determine the integer part */
if ((USARTx->CR1 & USART_CR1_OVER8) != 0)
{
/* Integer part computing in case Oversampling mode is 8 Samples */
integerdivider = ((25 * apbclock) / (2 * (USART_InitStruct->USART_BaudRate)));
}
else /* if ((USARTx->CR1 & USART_CR1_OVER8) == 0) */
{
/* Integer part computing in case Oversampling mode is 16 Samples */
integerdivider = ((25 * apbclock) / (4 * (USART_InitStruct->USART_BaudRate)));
}
tmpreg = (integerdivider / 100) << 4;
/* Determine the fractional part */
fractionaldivider = integerdivider - (100 * (tmpreg >> 4));
/* Implement the fractional part in the register */
if ((USARTx->CR1 & USART_CR1_OVER8) != 0)
{
tmpreg |= ((((fractionaldivider * 8) + 50) / 100)) & ((uint8_t)0x07);
}
else /* if ((USARTx->CR1 & USART_CR1_OVER8) == 0) */
{
tmpreg |= ((((fractionaldivider * 16) + 50) / 100)) & ((uint8_t)0x0F);
}
/* Write to USART BRR register */
USARTx->BRR = (uint16_t)tmpreg;
}
/**
* @brief Fills each USART_InitStruct member with its default value.
* @param USART_InitStruct: pointer to a USART_InitTypeDef structure which will
* be initialized.
* @retval None
*/
void USART_StructInit(USART_InitTypeDef* USART_InitStruct)
{
/* USART_InitStruct members default value */
USART_InitStruct->USART_BaudRate = 9600;
USART_InitStruct->USART_WordLength = USART_WordLength_8b;
USART_InitStruct->USART_StopBits = USART_StopBits_1;
USART_InitStruct->USART_Parity = USART_Parity_No ;
USART_InitStruct->USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
USART_InitStruct->USART_HardwareFlowControl = USART_HardwareFlowControl_None;
}
/**
* @brief Initializes the USARTx peripheral Clock according to the
* specified parameters in the USART_ClockInitStruct .
* @param USARTx: where x can be 1, 2, 3 or 6 to select the USART peripheral.
* @param USART_ClockInitStruct: pointer to a USART_ClockInitTypeDef structure that
* contains the configuration information for the specified USART peripheral.
* @note The Smart Card and Synchronous modes are not available for UART4 and UART5.
* @retval None
*/
void USART_ClockInit(USART_TypeDef* USARTx, USART_ClockInitTypeDef* USART_ClockInitStruct)
{
uint32_t tmpreg = 0x00;
/* Check the parameters */
assert_param(IS_USART_1236_PERIPH(USARTx));
assert_param(IS_USART_CLOCK(USART_ClockInitStruct->USART_Clock));
assert_param(IS_USART_CPOL(USART_ClockInitStruct->USART_CPOL));
assert_param(IS_USART_CPHA(USART_ClockInitStruct->USART_CPHA));
assert_param(IS_USART_LASTBIT(USART_ClockInitStruct->USART_LastBit));
/*---------------------------- USART CR2 Configuration -----------------------*/
tmpreg = USARTx->CR2;
/* Clear CLKEN, CPOL, CPHA and LBCL bits */
tmpreg &= (uint32_t)~((uint32_t)CR2_CLOCK_CLEAR_MASK);
/* Configure the USART Clock, CPOL, CPHA and LastBit ------------*/
/* Set CLKEN bit according to USART_Clock value */
/* Set CPOL bit according to USART_CPOL value */
/* Set CPHA bit according to USART_CPHA value */
/* Set LBCL bit according to USART_LastBit value */
tmpreg |= (uint32_t)USART_ClockInitStruct->USART_Clock | USART_ClockInitStruct->USART_CPOL |
USART_ClockInitStruct->USART_CPHA | USART_ClockInitStruct->USART_LastBit;
/* Write to USART CR2 */
USARTx->CR2 = (uint16_t)tmpreg;
}
/**
* @brief Fills each USART_ClockInitStruct member with its default value.
* @param USART_ClockInitStruct: pointer to a USART_ClockInitTypeDef structure
* which will be initialized.
* @retval None
*/
void USART_ClockStructInit(USART_ClockInitTypeDef* USART_ClockInitStruct)
{
/* USART_ClockInitStruct members default value */
USART_ClockInitStruct->USART_Clock = USART_Clock_Disable;
USART_ClockInitStruct->USART_CPOL = USART_CPOL_Low;
USART_ClockInitStruct->USART_CPHA = USART_CPHA_1Edge;
USART_ClockInitStruct->USART_LastBit = USART_LastBit_Disable;
}
/**
* @brief Enables or disables the specified USART peripheral.
* @param USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or
* UART peripheral.
* @param NewState: new state of the USARTx peripheral.
* This parameter can be: ENABLE or DISABLE.
* @retval None
*/
void USART_Cmd(USART_TypeDef* USARTx, FunctionalState NewState)
{
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
assert_param(IS_FUNCTIONAL_STATE(NewState));
if (NewState != DISABLE)
{
/* Enable the selected USART by setting the UE bit in the CR1 register */
USARTx->CR1 |= USART_CR1_UE;
}
else
{
/* Disable the selected USART by clearing the UE bit in the CR1 register */
USARTx->CR1 &= (uint16_t)~((uint16_t)USART_CR1_UE);
}
}
/**
* @brief Sets the system clock prescaler.
* @param USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or
* UART peripheral.
* @param USART_Prescaler: specifies the prescaler clock.
* @note The function is used for IrDA mode with UART4 and UART5.
* @retval None
*/
void USART_SetPrescaler(USART_TypeDef* USARTx, uint8_t USART_Prescaler)
{
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
/* Clear the USART prescaler */
USARTx->GTPR &= USART_GTPR_GT;
/* Set the USART prescaler */
USARTx->GTPR |= USART_Prescaler;
}
/**
* @brief Enables or disables the USART's 8x oversampling mode.
* @note This function has to be called before calling USART_Init() function
* in order to have correct baudrate Divider value.
* @param USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or
* UART peripheral.
* @param NewState: new state of the USART 8x oversampling mode.
* This parameter can be: ENABLE or DISABLE.
* @retval None
*/
void USART_OverSampling8Cmd(USART_TypeDef* USARTx, FunctionalState NewState)
{
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
assert_param(IS_FUNCTIONAL_STATE(NewState));
if (NewState != DISABLE)
{
/* Enable the 8x Oversampling mode by setting the OVER8 bit in the CR1 register */
USARTx->CR1 |= USART_CR1_OVER8;
}
else
{
/* Disable the 8x Oversampling mode by clearing the OVER8 bit in the CR1 register */
USARTx->CR1 &= (uint16_t)~((uint16_t)USART_CR1_OVER8);
}
}
/**
* @brief Enables or disables the USART's one bit sampling method.
* @param USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or
* UART peripheral.
* @param NewState: new state of the USART one bit sampling method.
* This parameter can be: ENABLE or DISABLE.
* @retval None
*/
void USART_OneBitMethodCmd(USART_TypeDef* USARTx, FunctionalState NewState)
{
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
assert_param(IS_FUNCTIONAL_STATE(NewState));
if (NewState != DISABLE)
{
/* Enable the one bit method by setting the ONEBITE bit in the CR3 register */
USARTx->CR3 |= USART_CR3_ONEBIT;
}
else
{
/* Disable the one bit method by clearing the ONEBITE bit in the CR3 register */
USARTx->CR3 &= (uint16_t)~((uint16_t)USART_CR3_ONEBIT);
}
}
/**
* @}
*/
/** @defgroup USART_Group2 Data transfers functions
* @brief Data transfers functions
*
@verbatim
===============================================================================
Data transfers functions
===============================================================================
This subsection provides a set of functions allowing to manage the USART data
transfers.
During an USART reception, data shifts in least significant bit first through
the RX pin. In this mode, the USART_DR register consists of a buffer (RDR)
between the internal bus and the received shift register.
When a transmission is taking place, a write instruction to the USART_DR register
stores the data in the TDR register and which is copied in the shift register
at the end of the current transmission.
The read access of the USART_DR register can be done using the USART_ReceiveData()
function and returns the RDR buffered value. Whereas a write access to the USART_DR
can be done using USART_SendData() function and stores the written data into
TDR buffer.
@endverbatim
* @{
*/
/**
* @brief Transmits single data through the USARTx peripheral.
* @param USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or
* UART peripheral.
* @param Data: the data to transmit.
* @retval None
*/
void USART_SendData(USART_TypeDef* USARTx, uint16_t Data)
{
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
assert_param(IS_USART_DATA(Data));
/* Transmit Data */
USARTx->DR = (Data & (uint16_t)0x01FF);
}
/**
* @brief Returns the most recent received data by the USARTx peripheral.
* @param USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or
* UART peripheral.
* @retval The received data.
*/
uint16_t USART_ReceiveData(USART_TypeDef* USARTx)
{
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
/* Receive Data */
return (uint16_t)(USARTx->DR & (uint16_t)0x01FF);
}
/**
* @}
*/
/** @defgroup USART_Group3 MultiProcessor Communication functions
* @brief Multi-Processor Communication functions
*
@verbatim
===============================================================================
Multi-Processor Communication functions
===============================================================================
This subsection provides a set of functions allowing to manage the USART
multiprocessor communication.
For instance one of the USARTs can be the master, its TX output is connected to
the RX input of the other USART. The others are slaves, their respective TX outputs
are logically ANDed together and connected to the RX input of the master.
USART multiprocessor communication is possible through the following procedure:
1. Program the Baud rate, Word length = 9 bits, Stop bits, Parity, Mode transmitter
or Mode receiver and hardware flow control values using the USART_Init()
function.
2. Configures the USART address using the USART_SetAddress() function.
3. Configures the wake up method (USART_WakeUp_IdleLine or USART_WakeUp_AddressMark)
using USART_WakeUpConfig() function only for the slaves.
4. Enable the USART using the USART_Cmd() function.
5. Enter the USART slaves in mute mode using USART_ReceiverWakeUpCmd() function.
The USART Slave exit from mute mode when receive the wake up condition.
@endverbatim
* @{
*/
/**
* @brief Sets the address of the USART node.
* @param USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or
* UART peripheral.
* @param USART_Address: Indicates the address of the USART node.
* @retval None
*/
void USART_SetAddress(USART_TypeDef* USARTx, uint8_t USART_Address)
{
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
assert_param(IS_USART_ADDRESS(USART_Address));
/* Clear the USART address */
USARTx->CR2 &= (uint16_t)~((uint16_t)USART_CR2_ADD);
/* Set the USART address node */
USARTx->CR2 |= USART_Address;
}
/**
* @brief Determines if the USART is in mute mode or not.
* @param USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or
* UART peripheral.
* @param NewState: new state of the USART mute mode.
* This parameter can be: ENABLE or DISABLE.
* @retval None
*/
void USART_ReceiverWakeUpCmd(USART_TypeDef* USARTx, FunctionalState NewState)
{
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
assert_param(IS_FUNCTIONAL_STATE(NewState));
if (NewState != DISABLE)
{
/* Enable the USART mute mode by setting the RWU bit in the CR1 register */
USARTx->CR1 |= USART_CR1_RWU;
}
else
{
/* Disable the USART mute mode by clearing the RWU bit in the CR1 register */
USARTx->CR1 &= (uint16_t)~((uint16_t)USART_CR1_RWU);
}
}
/**
* @brief Selects the USART WakeUp method.
* @param USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or
* UART peripheral.
* @param USART_WakeUp: specifies the USART wakeup method.
* This parameter can be one of the following values:
* @arg USART_WakeUp_IdleLine: WakeUp by an idle line detection
* @arg USART_WakeUp_AddressMark: WakeUp by an address mark
* @retval None
*/
void USART_WakeUpConfig(USART_TypeDef* USARTx, uint16_t USART_WakeUp)
{
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
assert_param(IS_USART_WAKEUP(USART_WakeUp));
USARTx->CR1 &= (uint16_t)~((uint16_t)USART_CR1_WAKE);
USARTx->CR1 |= USART_WakeUp;
}
/**
* @}
*/
/** @defgroup USART_Group4 LIN mode functions
* @brief LIN mode functions
*
@verbatim
===============================================================================
LIN mode functions
===============================================================================
This subsection provides a set of functions allowing to manage the USART LIN
Mode communication.
In LIN mode, 8-bit data format with 1 stop bit is required in accordance with
the LIN standard.
Only this LIN Feature is supported by the USART IP:
- LIN Master Synchronous Break send capability and LIN slave break detection
capability : 13-bit break generation and 10/11 bit break detection
USART LIN Master transmitter communication is possible through the following procedure:
1. Program the Baud rate, Word length = 8bits, Stop bits = 1bit, Parity,
Mode transmitter or Mode receiver and hardware flow control values using
the USART_Init() function.
2. Enable the USART using the USART_Cmd() function.
3. Enable the LIN mode using the USART_LINCmd() function.
4. Send the break character using USART_SendBreak() function.
USART LIN Master receiver communication is possible through the following procedure:
1. Program the Baud rate, Word length = 8bits, Stop bits = 1bit, Parity,
Mode transmitter or Mode receiver and hardware flow control values using
the USART_Init() function.
2. Enable the USART using the USART_Cmd() function.
3. Configures the break detection length using the USART_LINBreakDetectLengthConfig()
function.
4. Enable the LIN mode using the USART_LINCmd() function.
@note In LIN mode, the following bits must be kept cleared:
- CLKEN in the USART_CR2 register,
- STOP[1:0], SCEN, HDSEL and IREN in the USART_CR3 register.
@endverbatim
* @{
*/
/**
* @brief Sets the USART LIN Break detection length.
* @param USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or
* UART peripheral.
* @param USART_LINBreakDetectLength: specifies the LIN break detection length.
* This parameter can be one of the following values:
* @arg USART_LINBreakDetectLength_10b: 10-bit break detection
* @arg USART_LINBreakDetectLength_11b: 11-bit break detection
* @retval None
*/
void USART_LINBreakDetectLengthConfig(USART_TypeDef* USARTx, uint16_t USART_LINBreakDetectLength)
{
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
assert_param(IS_USART_LIN_BREAK_DETECT_LENGTH(USART_LINBreakDetectLength));
USARTx->CR2 &= (uint16_t)~((uint16_t)USART_CR2_LBDL);
USARTx->CR2 |= USART_LINBreakDetectLength;
}
/**
* @brief Enables or disables the USART's LIN mode.
* @param USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or
* UART peripheral.
* @param NewState: new state of the USART LIN mode.
* This parameter can be: ENABLE or DISABLE.
* @retval None
*/
void USART_LINCmd(USART_TypeDef* USARTx, FunctionalState NewState)
{
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
assert_param(IS_FUNCTIONAL_STATE(NewState));
if (NewState != DISABLE)
{
/* Enable the LIN mode by setting the LINEN bit in the CR2 register */
USARTx->CR2 |= USART_CR2_LINEN;
}
else
{
/* Disable the LIN mode by clearing the LINEN bit in the CR2 register */
USARTx->CR2 &= (uint16_t)~((uint16_t)USART_CR2_LINEN);
}
}
/**
* @brief Transmits break characters.
* @param USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or
* UART peripheral.
* @retval None
*/
void USART_SendBreak(USART_TypeDef* USARTx)
{
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
/* Send break characters */
USARTx->CR1 |= USART_CR1_SBK;
}
/**
* @}
*/
/** @defgroup USART_Group5 Halfduplex mode function
* @brief Half-duplex mode function
*
@verbatim
===============================================================================
Half-duplex mode function
===============================================================================
This subsection provides a set of functions allowing to manage the USART
Half-duplex communication.
The USART can be configured to follow a single-wire half-duplex protocol where
the TX and RX lines are internally connected.
USART Half duplex communication is possible through the following procedure:
1. Program the Baud rate, Word length, Stop bits, Parity, Mode transmitter
or Mode receiver and hardware flow control values using the USART_Init()
function.
2. Configures the USART address using the USART_SetAddress() function.
3. Enable the USART using the USART_Cmd() function.
4. Enable the half duplex mode using USART_HalfDuplexCmd() function.
@note The RX pin is no longer used
@note In Half-duplex mode the following bits must be kept cleared:
- LINEN and CLKEN bits in the USART_CR2 register.
- SCEN and IREN bits in the USART_CR3 register.
@endverbatim
* @{
*/
/**
* @brief Enables or disables the USART's Half Duplex communication.
* @param USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or
* UART peripheral.
* @param NewState: new state of the USART Communication.
* This parameter can be: ENABLE or DISABLE.
* @retval None
*/
void USART_HalfDuplexCmd(USART_TypeDef* USARTx, FunctionalState NewState)
{
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
assert_param(IS_FUNCTIONAL_STATE(NewState));
if (NewState != DISABLE)
{
/* Enable the Half-Duplex mode by setting the HDSEL bit in the CR3 register */
USARTx->CR3 |= USART_CR3_HDSEL;
}
else
{
/* Disable the Half-Duplex mode by clearing the HDSEL bit in the CR3 register */
USARTx->CR3 &= (uint16_t)~((uint16_t)USART_CR3_HDSEL);
}
}
/**
* @}
*/
/** @defgroup USART_Group6 Smartcard mode functions
* @brief Smartcard mode functions
*
@verbatim
===============================================================================
Smartcard mode functions
===============================================================================
This subsection provides a set of functions allowing to manage the USART
Smartcard communication.
The Smartcard interface is designed to support asynchronous protocol Smartcards as
defined in the ISO 7816-3 standard.
The USART can provide a clock to the smartcard through the SCLK output.
In smartcard mode, SCLK is not associated to the communication but is simply derived
from the internal peripheral input clock through a 5-bit prescaler.
Smartcard communication is possible through the following procedure:
1. Configures the Smartcard Prescaler using the USART_SetPrescaler() function.
2. Configures the Smartcard Guard Time using the USART_SetGuardTime() function.
3. Program the USART clock using the USART_ClockInit() function as following:
- USART Clock enabled
- USART CPOL Low
- USART CPHA on first edge
- USART Last Bit Clock Enabled
4. Program the Smartcard interface using the USART_Init() function as following:
- Word Length = 9 Bits
- 1.5 Stop Bit
- Even parity
- BaudRate = 12096 baud
- Hardware flow control disabled (RTS and CTS signals)
- Tx and Rx enabled
5. Optionally you can enable the parity error interrupt using the USART_ITConfig()
function
6. Enable the USART using the USART_Cmd() function.
7. Enable the Smartcard NACK using the USART_SmartCardNACKCmd() function.
8. Enable the Smartcard interface using the USART_SmartCardCmd() function.
Please refer to the ISO 7816-3 specification for more details.
@note It is also possible to choose 0.5 stop bit for receiving but it is recommended
to use 1.5 stop bits for both transmitting and receiving to avoid switching
between the two configurations.
@note In smartcard mode, the following bits must be kept cleared:
- LINEN bit in the USART_CR2 register.
- HDSEL and IREN bits in the USART_CR3 register.
@note Smartcard mode is available on USART peripherals only (not available on UART4
and UART5 peripherals).
@endverbatim
* @{
*/
/**
* @brief Sets the specified USART guard time.
* @param USARTx: where x can be 1, 2, 3 or 6 to select the USART or
* UART peripheral.
* @param USART_GuardTime: specifies the guard time.
* @retval None
*/
void USART_SetGuardTime(USART_TypeDef* USARTx, uint8_t USART_GuardTime)
{
/* Check the parameters */
assert_param(IS_USART_1236_PERIPH(USARTx));
/* Clear the USART Guard time */
USARTx->GTPR &= USART_GTPR_PSC;
/* Set the USART guard time */
USARTx->GTPR |= (uint16_t)((uint16_t)USART_GuardTime << 0x08);
}
/**
* @brief Enables or disables the USART's Smart Card mode.
* @param USARTx: where x can be 1, 2, 3 or 6 to select the USART or
* UART peripheral.
* @param NewState: new state of the Smart Card mode.
* This parameter can be: ENABLE or DISABLE.
* @retval None
*/
void USART_SmartCardCmd(USART_TypeDef* USARTx, FunctionalState NewState)
{
/* Check the parameters */
assert_param(IS_USART_1236_PERIPH(USARTx));
assert_param(IS_FUNCTIONAL_STATE(NewState));
if (NewState != DISABLE)
{
/* Enable the SC mode by setting the SCEN bit in the CR3 register */
USARTx->CR3 |= USART_CR3_SCEN;
}
else
{
/* Disable the SC mode by clearing the SCEN bit in the CR3 register */
USARTx->CR3 &= (uint16_t)~((uint16_t)USART_CR3_SCEN);
}
}
/**
* @brief Enables or disables NACK transmission.
* @param USARTx: where x can be 1, 2, 3 or 6 to select the USART or
* UART peripheral.
* @param NewState: new state of the NACK transmission.
* This parameter can be: ENABLE or DISABLE.
* @retval None
*/
void USART_SmartCardNACKCmd(USART_TypeDef* USARTx, FunctionalState NewState)
{
/* Check the parameters */
assert_param(IS_USART_1236_PERIPH(USARTx));
assert_param(IS_FUNCTIONAL_STATE(NewState));
if (NewState != DISABLE)
{
/* Enable the NACK transmission by setting the NACK bit in the CR3 register */
USARTx->CR3 |= USART_CR3_NACK;
}
else
{
/* Disable the NACK transmission by clearing the NACK bit in the CR3 register */
USARTx->CR3 &= (uint16_t)~((uint16_t)USART_CR3_NACK);
}
}
/**
* @}
*/
/** @defgroup USART_Group7 IrDA mode functions
* @brief IrDA mode functions
*
@verbatim
===============================================================================
IrDA mode functions
===============================================================================
This subsection provides a set of functions allowing to manage the USART
IrDA communication.
IrDA is a half duplex communication protocol. If the Transmitter is busy, any data
on the IrDA receive line will be ignored by the IrDA decoder and if the Receiver
is busy, data on the TX from the USART to IrDA will not be encoded by IrDA.
While receiving data, transmission should be avoided as the data to be transmitted
could be corrupted.
IrDA communication is possible through the following procedure:
1. Program the Baud rate, Word length = 8 bits, Stop bits, Parity, Transmitter/Receiver
modes and hardware flow control values using the USART_Init() function.
2. Enable the USART using the USART_Cmd() function.
3. Configures the IrDA pulse width by configuring the prescaler using
the USART_SetPrescaler() function.
4. Configures the IrDA USART_IrDAMode_LowPower or USART_IrDAMode_Normal mode
using the USART_IrDAConfig() function.
5. Enable the IrDA using the USART_IrDACmd() function.
@note A pulse of width less than two and greater than one PSC period(s) may or may
not be rejected.