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Diffstat (limited to 'libopencm3/lib/stm32/f3/usart.c')
| -rw-r--r-- | libopencm3/lib/stm32/f3/usart.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/libopencm3/lib/stm32/f3/usart.c b/libopencm3/lib/stm32/f3/usart.c new file mode 100644 index 0000000..305ae72 --- /dev/null +++ b/libopencm3/lib/stm32/f3/usart.c @@ -0,0 +1,140 @@ +/** @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; +} + +/**@}*/ |