S32k144 can not see any scope in I2c routine PTA2,PTA3.

[郑文豪]

Two pins always keep low level.Routine called S32K144_Project_LPI2C.I'm not connecting anything in two pins.

[Robin_Shen]

Hi 郑文豪,

Please refer "52.3.2.6 Pin Configuration" of S32K1xx MCU Family - Reference Manual .
External pull-up resistor are needed.

Best Regards,
Robin
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[郑文豪]

Code:

void PORT_init(void)

{

    /*!

     * Pins definitions

     * ===================================================

     *

     * Pin number        | Function

     * ----------------- |------------------

     * PTA2              | LPI2C_SDA

     * PTA3              | LPI2C_SCL

     * 

     */

PCC->PCCn[PCC_PORTA_INDEX ]|=PCC_PCCn_CGC_MASK;/* Enable PORTA*/

    PORTA->PCR[2]   |= PORT_PCR_MUX(3)      /* Port A2: MUX = ALT3, LPI2C_SDA */

                                               | PORT_PCR_PE_MASK   /* Pull resistor enable */

                                               | PORT_PCR_PS(1);    /* Pull up selected */

    PORTA->PCR[3]   |= PORT_PCR_MUX(3)      /* Port A3: MUX = ALT3, LPI2C_SCL */

                                                | PORT_PCR_PE_MASK  /* Pull resistor enable */

                                                | PORT_PCR_PS(1);   /* Pull up selected */

}

int main(void)

{

    /*!

     *

     *Initializations

     *=========================================

     */

SOSC_init_8MHz();      /* Initialize system oscillator for 8 MHz xtal */

SPLL_init_160MHz();    /* Initialize SPLL to 160 MHz with 8 MHz SOSC */

NormalRUNmode_80MHz(); /* Init clocks: 80 MHz sysclk & core, 40 MHz bus, 20 MHz flash */

PORT_init();           /* Configure */

LPI2C_init();          /* Initializes LPI2C ignoring NACK*/

    /*!

     *

     *Infinite for

     *=========================================

     */

        for(;;)

        {

        LPI2C_Transmit();/*Transmit ID*/

        }

}

void LPI2C_init(void)

{

    PCC->PCCn[PCC_LPI2C0_INDEX] |= PCC_PCCn_PCS(2)        /* Clk src: SIRCDIV2_CLK */

                              | PCC_PCCn_CGC_MASK;   /* Enable clock for LPI2C0 */

    LPI2C0->MCFGR1 = LPI2C_MCFGR1_PRESCALE(2) /* Prescale = 4*/

|LPI2C_MCFGR1_IGNACK_MASK;/* Ignore NACK*/

/* SCL_freq = Input_freq / (2^PRESCALER * (CLKLO + CLKHI + 2))*/

    LPI2C0->MCCR0 = LPI2C_MCCR0_CLKLO(18)

                | LPI2C_MCCR0_CLKHI(6)

                | LPI2C_MCCR0_SETHOLD(6)

                | LPI2C_MCCR0_DATAVD(3);

    LPI2C0->MFCR = LPI2C_MFCR_TXWATER(0) /* Transmitter Water mark set to 0*/

                  |LPI2C_MFCR_RXWATER(3); /* Receiver Water mark set to 3*/

    LPI2C0->MCR |= LPI2C_MCR_MEN_MASK /* Enable LPI2C as master */

            | LPI2C_MCR_DBGEN_MASK;

}

void LPI2C_Transmit (void)

{

LPI2C0->MTDR = (0x05<<8)|((0x1E<<1)|0);

}

[Robin_Shen · Accepted solution]

Would you please test it after external pull up resistor connected?
Internal pull up resistor may not work for I2C pins.

Best Regards,
Robin
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Note:
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