Hi everybody,
I am using STM32G070KB and trying to generate a LIN break. But this seems to be only 10 bits long instead of the described 13 bits.
If I am right the break should be about 680µs long at 19.2kBaud. But it is only about 520µs long which is only 10 bits.
I may have configured the USART incorrectly. I trigger the break with:
USART1->RQR |= (USART_RQR_SBKRQ);
Configuration:
void UART_Init(void)
{
UART1_CLK_EN(); /* UART3 Clock einschalten */
USART1->CR1 = 0x00000000; /* UART3 Konfiguration zurücksetzen */
USART1->CR2 = 0x00000000;
USART1->CR3 = 0x00000000;
USART1->BRR = 16000000u / BAUDRATE_KLINE; /* Baudrate auf 19200 setzen */
USART1->CR1 |= (USART_CR1_TE | USART_CR1_RE | USART_CR1_RXNEIE_RXFNEIE); /* TX und RX einschalten, RX Interrupt einschalten */
USART1->CR2 |= (USART_CR2_LINEN);
USART1->CR3 |= (USART_CR3_ONEBIT | USART_CR3_EIE | USART_CR3_DMAT); /* One Sample Bit Mode, Error Interrupts, DMA Transmitter einschalten */
RCC->AHBENR |= RCC_AHBENR_DMA1EN; /* DMA clock einschalten */
DMA1_Channel2->CCR = 0x00000000; /* DMA Konfiguration zurücksetzen */
DMA1_Channel2->CCR |= (DMA_CCR_MINC | DMA_CCR_DIR | DMA_CCR_TCIE); /* Speicheradresse inkrementieren | Von Memory zu Peripherie | Transfer Complete Interrupt aktivieren */
DMAMUX1_Channel1->CCR &= ~(DMAMUX_CxCR_DMAREQ_ID);
DMAMUX1_Channel1->CCR |= (DMAMUX_CxCR_DMAREQ_ID_51);
DMA1_Channel2->CPAR = (unsigned int)&USART1->TDR; /* DMA-Ziel -> UART1 */
DMA1_Channel2->CMAR = (unsigned int)UART_TX_Buffer; /* Lese Daten aus UART_TX_Buffer */
NVIC_SetPriority(USART1_IRQn, 3); /* Interruptpriorität für UART 1 setzen */
NVIC_EnableIRQ(USART1_IRQn); /* Interrupts für UART 1 aktivieren */
NVIC_SetPriority(DMA1_Channel2_3_IRQn, 3); /* Interruptpriorität für DMA-Kanal 2-3 setzen */
NVIC_EnableIRQ(DMA1_Channel2_3_IRQn); /* Interrupts für DMA-Kanal 2-3 aktivieren */
}
Thanks for the help.
