RW61X USART FIFOSTAT->RXTIMEOUT

[aar]

Working with RW612's USART I stumble into the following problem:

I'm enabling the USART RXTIMEOUT interrupt using the SDK-provided API:

USART_EnableInterrupts(USART3, kUSART_RxTimeoutInterruptEnable);

and I'm also setting the interrupt using the provided API to configure it:

    USART_CalcTimeoutConfig(timeMicroSec,
                            &rxTimeoutCfg.prescaler,
                            &rxTimeoutCfg.counter,
                            CLOCK_GetFlexCommClkFreq(flexCommId));
    rxTimeoutCfg.enable = true;
    rxTimeoutCfg.resetCounterOnEmpty = false;
    rxTimeoutCfg.resetCounterOnReceive = true;

    // Disable UART in order to configure timeout
    mp_uartBase->CFG &= ~USART_CFG_ENABLE_MASK;

    USART_SetRxTimeoutConfig(mp_uartBase, &rxTimeoutCfg);
    USART_EnableInterrupts(mp_uartBase, kUSART_RxTimeoutInterruptEnable);

    // Re-enable timeout
    mp_uartBase->CFG |= USART_CFG_ENABLE_MASK;

The interrupt is triggering as expected, however I'm unable to clear the interrupt.

According to RM00278 28.1.12:

However, from the fsl_usart.c driver (SDK 24.12) we have:

    /* Only TXERR, RXERR fields support write. Remaining fields should be set to zero */
    base->FIFOSTAT = mask & (USART_FIFOSTAT_TXERR_MASK | USART_FIFOSTAT_RXERR_MASK);

As the fsl driver wouldn't even attempt to clear write the FIFOSTAT->RXTIMEOUT timeout bit I tried to write to it directly:

        // Clear the timeout interrupt
        mp_uartBase->FIFOSTAT |= USART_FIFOSTAT_RXTIMEOUT_MASK;

Unfortunately, this doesn't work and the interrupt is never cleared.

Could you please advise on how RXTIMEOUT interrupt is cleared?

[Ricardo_Zamora]

Hello,

Hope you are doing well. Let me check this internally.

Best Regards,

Ricardo

[Ricardo_Zamora]

Hello,

Thank you for your patience!

I was able to clear that bit using the following code on the DEMO_USART_IRQHandler from the usart_interrupt example:

Best Regards,

Ricardo

[aar]

Ricardo,

Could you please share all the modifications you made to the example code? I'm still unable to clear this flag.

This is how I'm enabling RXTIMEOUT:

DoEnableRxTimeout(double timeoutBytes)
{
    const double rxTimeoutMicroSec{
      std::ceil(((timeoutBytes * m_transmissionSize) / m_baud) * 1000000)};

    usart_rx_timeout_config rxTimeoutCfg{};
    const std::uint32_t flexCommId{GetFlexcommId(mp_uartBase)};

    USART_CalcTimeoutConfig(static_cast<uint32_t>(rxTimeoutMicroSec),
                            &rxTimeoutCfg.prescaler,
                            &rxTimeoutCfg.counter,
                            CLOCK_GetFlexCommClkFreq(flexCommId));
    rxTimeoutCfg.enable = true;
    rxTimeoutCfg.resetCounterOnEmpty = false;
    rxTimeoutCfg.resetCounterOnReceive = true;

    // Disable UART to configure timeout
    mp_uartBase->CFG &= ~USART_CFG_ENABLE_MASK;

    USART_SetRxTimeoutConfig(mp_uartBase, &rxTimeoutCfg);
    USART_EnableInterrupts(mp_uartBase, kUSART_RxTimeoutInterruptEnable);

    // Re-enable UART
    mp_uartBase->CFG |= USART_CFG_ENABLE_MASK;
}

[Ricardo_Zamora]

Hello,

I just configured the timeout:

Regards,

Ricardo