topic Re: SPI interface error of MKL34Z64VLL4 in Kinetis Microcontrollers

SPI interface error of MKL34Z64VLL4

jtpark — Fri, 10 Mar 2017 06:10:50 GMT

Hello,

I tested spi interface with maxim device from MKL34Z64.

But I can't understand this issue.

Why that is only six clock of SCK?

Also, I send each 3 bytes, but only the same value is output continuously.

I use driver of fsl_spi.c (SPI_WriteData)

I attached project file.

Would you please let me know why occurred like this situation?

I must need to solve this problem.

thanks.

Original Attachment has been moved to: WIZIT_Flowmeter.zip

Re: SPI interface error of MKL34Z64VLL4

Hui_Ma — Tue, 14 Mar 2017 07:07:48 GMT

I checked your code, below code should be incorrect:

    SPI_WriteData(SPI1, (char)0x38);
   SPI_WriteData(SPI1, (char)0x13);
   SPI_WriteData(SPI1, (char)0x11);

There should wait previous SPI_WriteData() finished before call the next SPI_WriteData().

Please refer KSDK provided SPI example code, there call the SPI_WriteData() function in interrupt service routine:

void SPI_MASTER_IRQHandler(void)
{
    if (SPI_GetStatusFlags(EXAMPLE_SPI_MASTER) & kSPI_TxBufferEmptyFlag)
    {
        SPI_WriteData(EXAMPLE_SPI_MASTER, (uint16_t)(srcBuff[BUFFER_SIZE - masterIndex]));
        masterIndex--;
    }
    if (masterIndex == 0U)
    {
        masterFinished = true;
        SPI_DisableInterrupts(EXAMPLE_SPI_MASTER, kSPI_TxEmptyInterruptEnable);
    }
}

The SPI interrupt example could be found in below found:

..\SDK_2.0_FRDM-KL43Z\boards\frdmkl43z\driver_examples\spi\interrupt

Wish it helps.

Have a great day,
Ma Hui
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Re: SPI interface error of MKL34Z64VLL4

jtpark — Wed, 15 Mar 2017 09:59:18 GMT

Dear Hui_Ma,

Thank you for your support.

But I don't want to use an interrupt.
If i use a delay function, Is it ok?

SPI_WriteData(SPI1, (char)0x38);delay(10);
SPI_WriteData(SPI1, (char)0x13);delay(10);
SPI_WriteData(SPI1, (char)0x11);delay(10);

And I still don't understand spi waveform.(spi clk)

Thanks.

Best Regards,

JT Park

Re: SPI interface error of MKL34Z64VLL4

Hui_Ma — Mon, 20 Mar 2017 06:24:09 GMT

I had tested with FRDM-KL43Z board with SPI1 and FIFO mode enabled.

The KL34 SPI supports up to 8-byte-deep FIFO, so customer could call SPI_WriteData() to transmit data up to 8 times.

While, after customer call SPI_WriteData() function, it need to polling the SPIx_S[SPTEF] bit to make sure the SPI transmit Buffer(FIFO) empty.

When the SPI FIFO enabled, I could call below code to send 8 bytes out:

    SPI_WriteData(SPI1, 0x18);
    SPI_WriteData(SPI1, 0x28);
    SPI_WriteData(SPI1, 0x38);
    SPI_WriteData(SPI1, 0x48);
    SPI_WriteData(SPI1, 0x58);
    SPI_WriteData(SPI1, 0x68);
    SPI_WriteData(SPI1, 0x78);
    SPI_WriteData(SPI1, 0x88);

while(!(SPI1->S & SPI_S_SPTEF_MASK))
{}

I attached my test code for your reference.

When the SPI FIFO enabled, there doesn't need add delay() function between SPI_WriteData() function.

Wish it helps.

Re: SPI interface error of MKL34Z64VLL4

jtpark — Mon, 20 Mar 2017 07:01:27 GMT

Dear Hui_Ma,

Thank you for your reply.

I solved it.(I used SPI_WriteBlocking fuction.)

srcBuff[0] = 0x38;
srcBuff[1] = 0x13;
srcBuff[2] = 0x11;

SPI_WriteBlocking( SPI1, srcBuff, 3 );

I tested read function of SPI interface but it didn't work.

I used SPI_ReadData function of fsl_spi.c.

Would you please provide to me example code of read function?

Thanks.

Re: SPI interface error of MKL34Z64VLL4

Hui_Ma — Thu, 23 Mar 2017 06:06:19 GMT

For the SPI communication is TX/RX synchronize, when you need read SPI data, the SPI master need to transmit the dummy data at first. After that,then call SPI_ReadData() function to read received data.

Wish it helps.