MSP430F5438A: I2C Communication problem

Part Number: MSP430F5438A

hi, everyone.

My project is to send and receive 1 Byte to communicate with one MSP430 through I2C Communication.

I have configurated UCB0 I2C(P3.1,P3.2, Master), UCB1 I2C(P3.7, P5.4), transmission speed at 400Kbps and SMCLK at 1MHz. 

I have coded with driverlib of CCS.

It was working. But there are  problems. 

Blue is I2C_SDA and Yellow is I2C_SCL.

1) Frequency of SCL is 203.2KHz. I think the I2C_SCL should come close to 400KHZ. Because I set up  400Kbps.

USCI_B_I2C_initMasterParam I2cParam0 = {0,};
I2cParam0.selectClockSource = USCI_B_I2C_CLOCKSOURCE_SMCLK;
I2cParam0.i2cClk = UCS_getSMCLK();
I2cParam0.dataRate = USCI_B_I2C_SET_DATA_RATE_400KBPS;

USCI_B_I2C_initMaster(USCI_B0_BASE, &I2cParam0);

2) What does 1bit mean between Data Address and NACK ?

3) Is the NACK data signal normally this short? The NACK value could not be maintained for 1 clock.

This is my code.

#include <MSP430.h>
#include <MSP430F5xx_6xx/driverlib.h>

uint8_t transmitData = 0x52;
uint8_t receiveData;
/**
 * main.c
 */
void main(void)
{
	WDT_A_hold(WDT_A_BASE);// stop watchdog timer

	initGPIO();
	initClock();
	initI2C();

	__bis_SR_register(GIE);
	while(1)
	{
		USCI_B_I2C_masterSendSingleByte(USCI_B0_BASE, transmitData);

		while(USCI_B_I2C_isBusBusy(USCI_B0_BASE));

		//__delay_cycles(50);

		transmitData++;
	}
}



#pragma vector = USCI_B1_VECTOR
__interrupt void USCI_B1_ISR(void)
{
	switch(__even_in_range(UCB1IV, 0x0A)){
		case 0x0A:
			receiveData = USCI_B_I2C_slaveGetData(USCI_B1_BASE);
			break;
	default: //__never_executed();
	break;
	}
}

#include <MSP430F5xx_6xx/driverlib.h>

// Clock
#define XT1CLK_HZ 32768
#define XT2CLK_HZ 32768
#define DESIREDMCLK_KHZ 1000
#define MCLKXT1CLKRATIO	DESIREDMCLK_KHZ/(XT1CLK_HZ/1024)

// I2C Slave
#define SLAVEADDRESS 0x51

uint32_t myACLK, mySMCLK, myMCLK;


void initGPIO(void)
{
	//Configurate oscillator 
	GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P7, GPIO_PIN0 + GPIO_PIN1);

	//Configurate I2C
	GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P3, GPIO_PIN1 + GPIO_PIN2 + GPIO_PIN7);
	GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P5, GPIO_PIN4);

	//Configurate SMCLK
	//GPIO_setAsPeripheralModuleFunctionOutputPin(GPIO_PORT_P11, GPIO_PIN2);
}

	

void initClock(void)
{
	PMM_setVCore(PMM_CORE_LEVEL_3);

	UCS_setExternalClockSource(XT1CLK_HZ, XT2CLK_HZ);
	UCS_turnOnLFXT1(XT1DRIVE_0, XCAP_3);

	UCS_initClockSignal(UCS_ACLK, UCS_XT1CLK_SELECT, UCS_CLOCK_DIVIDER_1);

	//Configurate FLL

	UCS_initClockSignal(UCS_FLLREF, UCS_XT1CLK_SELECT, UCS_CLOCK_DIVIDER_1);
	UCS_initFLL(DESIREDMCLK_KHZ, MCLKXT1CLKRATIO);

	myACLK = UCS_getACLK();
	mySMCLK = UCS_getSMCLK();
	myMCLK = UCS_getMCLK();
}

void initI2C(void)
{
	USCI_B_I2C_initMasterParam I2cParam0 = {0,};
	I2cParam0.selectClockSource = USCI_B_I2C_CLOCKSOURCE_SMCLK;
	I2cParam0.i2cClk = UCS_getSMCLK();
	I2cParam0.dataRate = USCI_B_I2C_SET_DATA_RATE_400KBPS;

	USCI_B_I2C_initMaster(USCI_B0_BASE, &I2cParam0);
	USCI_B_I2C_initSlave(USCI_B1_BASE, SLAVEADDRESS);

	USCI_B_I2C_setSlaveAddress(USCI_B0_BASE, SLAVEADDRESS);

	USCI_B_I2C_setMode(USCI_B0_BASE, USCI_B_I2C_TRANSMIT_MODE);
	USCI_B_I2C_setMode(USCI_B1_BASE, USCI_B_I2C_RECEIVE_MODE);

	USCI_B_I2C_enable(USCI_B0_BASE);
	USCI_B_I2C_enable(USCI_B1_BASE);

	USCI_B_I2C_clearInterrupt(USCI_B0_BASE, USCI_B_I2C_TRANSMIT_INTERRUPT);
	USCI_B_I2C_clearInterrupt(USCI_B1_BASE, USCI_B_I2C_RECEIVE_INTERRUPT);

	USCI_B_I2C_enableInterrupt(USCI_B0_BASE, USCI_B_I2C_TRANSMIT_INTERRUPT);
	USCI_B_I2C_enableInterrupt(USCI_B1_BASE, USCI_B_I2C_RECEIVE_INTERRUPT);
}