K60 SPI Chip Select Problem ? PCS(0) not asserted in DSPI0 module

yanam — Tue, 14 May 2013 09:05:29 GMT

Hello

I am able to generate clock and data using the following code. However the chip-select is not triggered or asserted automatically. I believe I am missing something, can anyone point out.

Initialization Code:

SPISelectPtr = SPI0_BASE_PTR;
            // Turn on the clock
            SIM_SCGC6 |= SIM_SCGC6_DSPI0_MASK;
       
            // Select pins
            // Clock
            PORTC_PCR5 &= (~PORT_PCR_MUX_MASK);
            PORTC_PCR5 = PORT_PCR_MUX(2) | PORT_PCR_DSE_MASK | PORT_PCR_PE_MASK | PORT_PCR_PS_MASK;
            // Sout
            PORTC_PCR6 &= (~PORT_PCR_MUX_MASK);
            PORTC_PCR6 = PORT_PCR_MUX(2) | PORT_PCR_DSE_MASK | PORT_PCR_PE_MASK | PORT_PCR_PS_MASK;
            // Sin
            PORTC_PCR7 &= (~PORT_PCR_MUX_MASK);
            PORTC_PCR7 = PORT_PCR_MUX(2) | PORT_PCR_DSE_MASK | PORT_PCR_PE_MASK | PORT_PCR_PS_MASK;
       
            //Chip Select 0
            PORTD_PCR0 &= (~PORT_PCR_MUX_MASK);
            PORTD_PCR0 = PORT_PCR_MUX(2) | PORT_PCR_DSE_MASK | PORT_PCR_PE_MASK | PORT_PCR_PS_MASK;;
       
            PORTD_PCR4 &= (~PORT_PCR_MUX_MASK);
            PORTD_PCR4 = PORT_PCR_MUX(2) | PORT_PCR_DSE_MASK | PORT_PCR_PE_MASK | PORT_PCR_PS_MASK;;

    // Select Master Mode
    // Continous Clock is disabled
    // FRZ is disabled, can be enabled later using SPI_MCR_FRZ_MASK
    SPI_MCR_REG(SPISelectPtr) = (SPI_MCR_DCONF(0) | SPI_MCR_MSTR_MASK | SPI_MCR_PCSIS(0) | SPI_MCR_PCSIS(1) | SPI_MCR_PCSIS(2)
                                | SPI_MCR_CLR_TXF_MASK | SPI_MCR_CLR_RXF_MASK);

    // Frame Size = 8
    // CPOL = 1
    // CPHA = 1
    // Delay after Transfer Prescaler value is 5
    // Baud Rate Prescaler value is 1
    SPI_CTAR_REG(SPISelectPtr, 0) = SPI_CTAR_FMSZ(8) | SPI_CTAR_CPOL_MASK | SPI_CTAR_CPHA_MASK | SPI_CTAR_PDT(2) | SPI_CTAR_BR(6);

Test Function to call byte write

void vTestWriteByteToSPI(uint8_t u8Data, uint8_t chip_select)
{
    SPI_MemMapPtr SPISelectPtr = SPI0_BASE_PTR;


    // Making sure no chip select beyond 0 and 1
    chip_select &= 1;
    // Write a byte with CS0
    SPI_PUSHR_REG(SPISelectPtr) = SPI_PUSHR_TXDATA(u8Data) | SPI_PUSHR_CONT_MASK | SPI_PUSHR_CTAS(0) | SPI_PUSHR_PCS(chip_select + 1);
    // Wait Until Read Flag
    while (!( SPI_SR_REG(SPISelectPtr) & SPI_SR_RFDF_MASK ));
    // Clear Read Flag
    SPI_SR_REG(SPISelectPtr) |= SPI_SR_RFDF_MASK;


}

I am using Freescale ARM Compiler, CodeWarrior 10.4. There are pull ups on the board for CS pins. Please help pointing out mistake if any.

Re: K60 SPI Chip Select Problem ? PCS(0) not asserted in DSPI0 module

yanam — Tue, 14 May 2013 11:36:17 GMT

The SPI_PUSHR_CONT_MASK was a problem. After removing it from OR switches, chip select is working perfect. I have improved the code now, if anybodys interested, will post it.

Re: K60 SPI Chip Select Problem ? PCS(0) not asserted in DSPI0 module

prajnithkumar — Fri, 02 Aug 2013 08:03:09 GMT

Hi Yogenda,

It will be really helpful if you could post the improved code which you have mentioned, I'm beginner on Kinetis development and having hard time finding SPI driver.

Thanks in Advance

topic Re: K60 SPI Chip Select Problem ? PCS(0) not asserted in DSPI0 module in Kinetis Microcontrollers

K60 SPI Chip Select Problem ? PCS(0) not asserted in DSPI0 module

Re: K60 SPI Chip Select Problem ? PCS(0) not asserted in DSPI0 module

Re: K60 SPI Chip Select Problem ? PCS(0) not asserted in DSPI0 module