nbh520的帖子 ST意法半导体中文论坛

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STemwin自定义GB2312编码汉字字库，字体放大问题

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nbh520 回答时间： 2018-11-6 13:48

baiyongbin2009 发表于 2018-11-6 11:50 这个是早期UCGUI3.XX时代预留下来的方案，放大效果的确有问题。建议还是直接生成对应的大字体吧，因为这 ... 好的，谢谢哥们解答

4 回答

STM32F411 DMA2 keil调试时，能够使用，不调试，就没有反应

STM32F4

nbh520 最优答案回答时间： 2017-11-7 16:57

使用DMA做串口接收时，在启动DMA后需要将串口溢出标志清除(有些应用场景，串口接收端是一直有数据存在的)，才能正常接收。这个问题之前在使用STM32L072时，就已经发现解决了，但由于F4平台和L0平台在清除溢出标志方式略有不同。为了避免有人出现同样的问题，下面给大家描述一下，两者的不同之处：STM32L0清除USART标志直接调用__HAL_USART_CLEAR_IT()即可 STM32F4 __HAL_UART_CLEAR_FLAG()能够清除的标志只有UART_FLAG_CTS、UART_FLAG_LBD、UART_FLAG_TC、UART_FLAG_RXNE，而PE (Parity error), FE (Framing error), NE (Noise error), ORE (Overrun error) and IDLE (Idle line detected) flags 等标志的清除需要读取USART_SR register才行。 STM32L0 /** @brief Clears the specified USART ISR flag, in setting the proper ICR register flag. * @param __HANDLE__: specifies the USART Handle which can be USART1 or USART2. * @param __IT_CLEAR__: specifies the interrupt clear register flag that needs to be set * to clear the corresponding interrupt * This parameter can be one of the following values: * @arg USART_CLEAR_PEF: Parity Error Clear Flag * @arg USART_CLEAR_FEF: Framing Error Clear Flag * @arg USART_CLEAR_NEF: Noise detected Clear Flag * @arg USART_CLEAR_OREF: OverRun Error Clear Flag * @arg USART_CLEAR_IDLEF: IDLE line detected Clear Flag * @arg USART_CLEAR_TCF: Transmission Complete Clear Flag * @arg USART_CLEAR_CTSF: CTS Interrupt Clear Flag * @retval None */ #define __HAL_USART_CLEAR_IT(__HANDLE__, __IT_CLEAR__) ((__HANDLE__)->Instance->ICR = (uint32_t)(__IT_CLEAR__)) STM32F4 /** @brief Clears the specified UART pending flag. * @param __HANDLE__: specifies the UART Handle. * This parameter can be UARTx where x: 1, 2, 3, 4, 5, 6, 7 or 8 to select the USART or * UART peripheral. * @param __FLAG__: specifies the flag to check. * This parameter can be any combination of the following values: * @arg UART_FLAG_CTS: CTS Change flag (not available for UART4 and UART5). * @arg UART_FLAG_LBD: LIN Break detection flag. * @arg UART_FLAG_TC: Transmission Complete flag. * @arg UART_FLAG_RXNE: Receive data register not empty flag. * * @note E (Parity error), FE (Framing error), NE (Noise error), ORE (Overrun * error) and IDLE (Idle line detected) flags are cleared by software * sequence: a read operation to USART_SR register followed by a read * operation to USART_DR register. * @note RXNE flag can be also cleared by a read to the USART_DR register. * @note TC flag can be also cleared by software sequence: a read operation to * USART_SR register followed by a write operation to USART_DR register. * @note TXE flag is cleared only by a write to the USART_DR register. * * @retval None */ #define __HAL_UART_CLEAR_FLAG(__HANDLE__, __FLAG__) ((__HANDLE__)->Instance->SR = ~(__FLAG__)) 复制代码

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