RT1061 LPSPI写TCR中的CONT和CPNTC位不生效

[TheSix]

下面这张图是我在函数中设置CONT和CONTC位为0：

从串口输出界面可以看出，函数的设置并未生效。但是是我在另外的函数进行相同的设置却是可以生效的，这是为什么呢？如下图：

下面是我的未生效的函数代码的实现：

status_t FRAM_read(uint32_t address, uint32_t* buffer, uint32_t size)

{

    status_t status = kStatus_Success;

    uint32_t addr_low  = address & 0xff;

    uint32_t addr_high = address >> 8;

    uint32_t transfer_size    = size;

    uint32_t* transfer_buffer = buffer;

   /* Check that LPSPI is not busy. */

    if((LPSPI_GetStatusFlags(LPSPI1) & (uint32_t)kLPSPI_ModuleBusyFlag) != 0U)

    {

        return kStatus_LPSPI_Busy;

    }

    /* flush fifo. clear status flag. */

    LPSPI_FlushFifo(LPSPI1, true, true);

    LPSPI_ClearStatusFlags(LPSPI1, (uint32_t)kLPSPI_AllStatusFlag);

    PRINTF("1 SR:%x, TCR:%x\r\n", LPSPI1->SR, LPSPI1->TCR);

    /* start transfer.PCS is assered and RXMASK is de-assered. */

    LPSPI1->TCR |= LPSPI_TCR_CONT(true)|LPSPI_TCR_CONTC(true)|LPSPI_TCR_RXMSK(true);

    /*TCR is also shared the FIFO, so wait for TCR written.*/

    if (!LPSPI_WaitTxFifoEmpty(LPSPI1))

    {

        return kStatus_LPSPI_Timeout;

    }

    PRINTF("2 SR:%x, TCR:%x\r\n", LPSPI1->SR, LPSPI1->TCR);

    /* send read opcode and RXMASK is de-assered to start recieve data. */

    LPSPI_WriteData(LPSPI1, READ_OPCODE);

    LPSPI_WriteData(LPSPI1, addr_high);

    LPSPI_WriteData(LPSPI1, addr_low);

    LPSPI1->TCR &= (uint32_t)~LPSPI_TCR_RXMSK_MASK;

    if (!LPSPI_WaitTxFifoEmpty(LPSPI1))

    {

        return kStatus_LPSPI_Timeout;

    }

    PRINTF("3 SR:%x, TCR:%x\r\n", LPSPI1->SR, LPSPI1->TCR);

    while(transfer_size > 0)

    {

        LPSPI_WriteData(LPSPI1, (uint32_t)0);

        if((LPSPI_GetStatusFlags(LPSPI1) & (uint32_t)kLPSPI_RxDataReadyFlag) != 0U)

        {

           *transfer_buffer = LPSPI_ReadData(LPSPI1);

           //PRINTF("recieve data %d:%x\r\n", (size-transfer_size), *transfer_buffer);

           transfer_size--;

           transfer_buffer++;

        }

    }

    LPSPI1->TCR &= ~(LPSPI_TCR_CONTC_MASK | LPSPI_TCR_CONT_MASK);

    if (!LPSPI_WaitTxFifoEmpty(LPSPI1))

    {

        return kStatus_LPSPI_Timeout;

    }

    PRINTF("4 SR:%x, TCR:%x\r\n", LPSPI1->SR, LPSPI1->TCR);

    return status;

}

[davenadler · Accepted solution]

I don't read Chinese but this might help:
https://community.nxp.com/t5/i-MX-RT/LPSPI-bugs-around-TCR-More-FSL-library-bugs-plus-an-LPSPI/td-p/... 

[TheSix]

Thank you, this is very inspiring to me.

[davenadler]

Glad to help, Don't forget to click "Kudos" on my posts!

It would be great if NXP would fix the FSL drivers - this is apparently a known problem (but not documented in errata nor fixed in FSL).

Best Regards, Dave

[Gavin_Jia]

Hi @TheSix ，

从这个输出来看确实很奇怪。可以尝试加一个打印在if语句之前吗？应该置位是成功的，如果这样是不是说明在等待TxFifo发送的时候又被其他函数改变了？

Best regards,
Gavin

[TheSix]

在if之前打印TCR的值也是同样的结果，写TCR寄存器的值并未生效。而且在代码中并没有在其他的地方再修改这个TCR的值。这个问题太奇怪了。

[Gavin_Jia]

尝试一下先禁用中断再修改寄存器呢？等处理逻辑结束之后再使能中断。

[TheSix]

我的程序中并没有开启任何中断，并且仅仅只使用了LPSPI这一个外设。尽管如此，我还是去尝试禁用了中断，但是仍然结果仍然是一样的。