topic MKE02Z Master RX SPI issue in Kinetis Microcontrollers

MKE02Z Master RX SPI issue

neilporven — Fri, 14 Oct 2016 04:02:34 GMT

Hi everyone,

I am having a bit of an issue with the SPI RX(reading data). I have the following code:

1. while (!(SPI1_S & SPI_S_SPTEF_MASK))
{}

2. SPI1_D = 0xFF; //Generate clocks, this shift data in

3. //Wait until SPRF clears
while ((SPI1_S & SPI_S_SPRF_MASK))
{}

4. ucData_Read = SPI1_D; //Get the data

surprising enough, if I step through it, I get the data I need. If I let it run, then my data is 0xFF, which is what I initialize

ucData_Read with. This is what I understood from the manual section of the SPI. If the SPTEF is set, then the transmit buffer is empty and the D register is ready to receive data, this is what I am doing with step 1. In step 2, I generate clocks

to shift data in (I can see the clocks and data in my oscilloscope). If the SPRF is set data is waiting to be read, this is what

I am doing in step 3. Finally in step 4, I read the data.

Can someone tell me if I am missing something?

Thanks.

Re: MKE02Z Master RX SPI issue

kerryzhou — Fri, 14 Oct 2016 08:36:39 GMT

Hi Neil,

Please modify your code like this:

1. while (!(SPI1_S & SPI_S_SPTEF_MASK))
{}

2. SPI1_D = 0xFF; //Generate clocks, this shift data in

3. //Wait until SPRF clears
while (!(SPI1_S & SPI_S_SPRF_MASK))
{}

4. ucData_Read = SPI1_D; //Get the data

You use the wrong code configuration, it should be when the SPI Read Buffer Full Flag=0, it should wait for the received data comming, otherwise, SPIx_S[SPRF]=1 means the data available in the receive data buffer.

Please modify it and test it again.

If you still have question, please let me know!

Have a great day,
Kerry

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