diff options
| -rw-r--r-- | libmaple/usart_private.h | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/libmaple/usart_private.h b/libmaple/usart_private.h index 8e8e11b..9bc0527 100644 --- a/libmaple/usart_private.h +++ b/libmaple/usart_private.h @@ -38,14 +38,21 @@ #include <libmaple/usart.h> static __always_inline void usart_irq(ring_buffer *rb, usart_reg_map *regs) { + /* We can get RXNE and ORE interrupts here. Only RXNE signifies + * availability of a byte in DR. + * + * See table 198 (sec 27.4, p809) in STM document RM0008 rev 15. + * We enable RXNEIE. */ + if (regs->SR & USART_SR_RXNE) { #ifdef USART_SAFE_INSERT - /* If the buffer is full and the user defines USART_SAFE_INSERT, - * ignore new bytes. */ - rb_safe_insert(rb, (uint8)regs->DR); + /* If the buffer is full and the user defines USART_SAFE_INSERT, + * ignore new bytes. */ + rb_safe_insert(rb, (uint8)regs->DR); #else - /* By default, push bytes around in the ring buffer. */ - rb_push_insert(rb, (uint8)regs->DR); + /* By default, push bytes around in the ring buffer. */ + rb_push_insert(rb, (uint8)regs->DR); #endif + } } uint32 _usart_clock_freq(usart_dev *dev); |