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/** @defgroup usart_file USART
*
* @ingroup STM32F3xx
*
* @brief <b>libopencm3 STM32F3xx USART</b>
*
* @version 1.0.0
*
* @date 30 August 2012
*
* LGPL License Terms @ref lgpl_license
*/
/*
* This file is part of the libopencm3 project.
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include <libopencm3/stm32/usart.h>
/*---------------------------------------------------------------------------*/
/** @brief USART Send a Data Word.
*
* @param[in] usart unsigned 32 bit. USART block register address base @ref
* usart_reg_base
* @param[in] data unsigned 16 bit.
*/
void usart_send(uint32_t usart, uint16_t data)
{
/* Send data. */
USART_TDR(usart) = (data & USART_TDR_MASK);
}
/*---------------------------------------------------------------------------*/
/** @brief USART Read a Received Data Word.
*
* If parity is enabled the MSB (bit 7 or 8 depending on the word length) is
* the parity bit.
*
* @param[in] usart unsigned 32 bit. USART block register address base @ref
* usart_reg_base
* @returns unsigned 16 bit data word.
*/
uint16_t usart_recv(uint32_t usart)
{
/* Receive data. */
return USART_RDR(usart) & USART_RDR_MASK;
}
/*---------------------------------------------------------------------------*/
/** @brief USART Wait for Transmit Data Buffer Empty
*
* Blocks until the transmit data buffer becomes empty and is ready to accept
* the next data word.
*
* @param[in] usart unsigned 32 bit. USART block register address base @ref
* usart_reg_base
*/
void usart_wait_send_ready(uint32_t usart)
{
/* Wait until the data has been transferred into the shift register. */
while ((USART_ISR(usart) & USART_ISR_TXE) == 0);
}
/*---------------------------------------------------------------------------*/
/** @brief USART Wait for Received Data Available
*
* Blocks until the receive data buffer holds a valid received data word.
*
* @param[in] usart unsigned 32 bit. USART block register address base @ref
* usart_reg_base
*/
void usart_wait_recv_ready(uint32_t usart)
{
/* Wait until the data is ready to be received. */
while ((USART_ISR(usart) & USART_ISR_RXNE) == 0);
}
/*---------------------------------------------------------------------------*/
/** @brief USART Read a Status Flag.
*
* @param[in] usart unsigned 32 bit. USART block register address base @ref
* usart_reg_base
* @param[in] flag Unsigned int32. Status register flag @ref usart_sr_flags.
* @returns boolean: flag set.
*/
bool usart_get_flag(uint32_t usart, uint32_t flag)
{
return ((USART_ISR(usart) & flag) != 0);
}
/*---------------------------------------------------------------------------*/
/** @brief USART Return Interrupt Source.
*
* Returns true if the specified interrupt flag (IDLE, RXNE, TC, TXE or OE) was
* set and the interrupt was enabled. If the specified flag is not an interrupt
* flag, the function returns false.
*
* @todo These are the most important interrupts likely to be used. Others
* relating to LIN break, and error conditions in multibuffer communication,
* need to be added for completeness.
*
* @param[in] usart unsigned 32 bit. USART block register address base @ref
* usart_reg_base
* @param[in] flag Unsigned int32. Status register flag @ref usart_sr_flags.
* @returns boolean: flag and interrupt enable both set.
*/
bool usart_get_interrupt_source(uint32_t usart, uint32_t flag)
{
uint32_t flag_set = (USART_ISR(usart) & flag);
/* IDLE, RXNE, TC, TXE interrupts */
if ((flag >= USART_ISR_IDLE) && (flag <= USART_ISR_TXE)) {
return ((flag_set & USART_CR1(usart)) != 0);
/* Overrun error */
} else if (flag == USART_ISR_ORE) {
return flag_set && (USART_CR3(usart) & USART_CR3_CTSIE);
}
return false;
}
/**@}*/
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