/**
* Interrupt handler for the USART1 peripheral.
*
* If the interrupt was caused by a received character, the handler adds the
* chararacter to the rx_buffer. If the interrupt was caused by the peripheral
* being ready to send a character, the handler takes one from the tx_buffer,
* and writes it to the peripheral. In case the interrupt was caused by a USART
* peripheral buffer overrun (typically happens during debugging), the handler
* clears that interrupt flag.
*/
void usart1_isr(void)
{
if (usart_get_flag(USART1, USART_ISR_RXNE)) {
char ch = (char) usart_recv(USART1);
os_char_buffer_write_ch(&bsp_rx_buffer, ch);
} else if (usart_get_flag(USART1, USART_ISR_TXE)) {
char ch = '\0';
if (os_char_buffer_read_ch(&bsp_tx_buffer, &ch)) {
usart_send(USART1, (uint8_t) ch);
} else {
usart_disable_tx_interrupt(USART1);
}
} else if (usart_get_flag(USART1, USART_ISR_ORE)) {
USART_ICR(USART1) |= USART_ICR_ORECF;
}
}
void usart_clear_rx_interrupt(uint32_t usart_base)
{
USART_ICR(usart_base) |= USART_ICR_ORECF;
}
void usart_clear_tx_interrupt(uint32_t usart_base)
{
USART_ICR(usart_base) |= USART_ICR_TCCF;
}
