diff options
| -rw-r--r-- | ports/rp2/machine_uart.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/ports/rp2/machine_uart.c b/ports/rp2/machine_uart.c index 044c905ff..dae57012a 100644 --- a/ports/rp2/machine_uart.c +++ b/ports/rp2/machine_uart.c @@ -140,8 +140,27 @@ static inline void read_mutex_unlock(machine_uart_obj_t *u) { STATIC void uart_drain_rx_fifo(machine_uart_obj_t *self) { if (read_mutex_try_lock(self)) { while (uart_is_readable(self->uart) && ringbuf_free(&self->read_buffer) > 0) { - // get a byte from uart and put into the buffer - ringbuf_put(&(self->read_buffer), uart_get_hw(self->uart)->dr); + // Get a byte from uart and put into the buffer. Every entry from + // the FIFO is accompanied by 4 error bits, that may be used for + // error handling. + uint16_t c = uart_get_hw(self->uart)->dr; + if (c & UART_UARTDR_OE_BITS) { + // Overrun Error: We missed at least one byte. Not much we can do here. + } + if (c & UART_UARTDR_BE_BITS) { + // Break Error: RX was held low for longer than one character + // (11 bits). We did *not* read the zero byte that we seemed to + // read from dr. + continue; + } + if (c & UART_UARTDR_PE_BITS) { + // Parity Error: The byte we read is invalid. + } + if (c & UART_UARTDR_FE_BITS) { + // Framing Error: We did not receive a valid stop bit. + } + + ringbuf_put(&(self->read_buffer), c); } read_mutex_unlock(self); } |