You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
31 lines
1.3 KiB
31 lines
1.3 KiB
// ***************************** Interrupt handlers *****************************
|
|
|
|
void uart_tx_ring(uart_ring *q){
|
|
ENTER_CRITICAL();
|
|
// Send out next byte of TX buffer
|
|
if (q->w_ptr_tx != q->r_ptr_tx) {
|
|
// Only send if transmit register is empty (aka last byte has been sent)
|
|
if ((q->uart->SR & USART_SR_TXE) != 0U) {
|
|
q->uart->DR = q->elems_tx[q->r_ptr_tx]; // This clears TXE
|
|
q->r_ptr_tx = (q->r_ptr_tx + 1U) % q->tx_fifo_size;
|
|
}
|
|
|
|
// Enable TXE interrupt if there is still data to be sent
|
|
if(q->r_ptr_tx != q->w_ptr_tx){
|
|
q->uart->CR1 |= USART_CR1_TXEIE;
|
|
} else {
|
|
q->uart->CR1 &= ~USART_CR1_TXEIE;
|
|
}
|
|
}
|
|
EXIT_CRITICAL();
|
|
}
|
|
|
|
// This read after reading SR clears all error interrupts. We don't want compiler warnings, nor optimizations
|
|
#define UART_READ_DR(uart) volatile uint8_t t = (uart)->DR; UNUSED(t);
|
|
|
|
// ***************************** Hardware setup *****************************
|
|
|
|
#define DIV_(_PCLK_, _BAUD_) (((_PCLK_) * 25U) / (4U * (_BAUD_)))
|
|
#define DIVMANT_(_PCLK_, _BAUD_) (DIV_((_PCLK_), (_BAUD_)) / 100U)
|
|
#define DIVFRAQ_(_PCLK_, _BAUD_) ((((DIV_((_PCLK_), (_BAUD_)) - (DIVMANT_((_PCLK_), (_BAUD_)) * 100U)) * 16U) + 50U) / 100U)
|
|
#define USART_BRR_(_PCLK_, _BAUD_) ((DIVMANT_((_PCLK_), (_BAUD_)) << 4) | (DIVFRAQ_((_PCLK_), (_BAUD_)) & 0x0FU))
|
|
|