i2c is not working for Tiva C TM4C123GXL and 24C04 (EEPROM)

[hamid159]

Hi guyz,
I am trying to run i2c on Tiva C TM4C123GXL board. After Initiating the communication, Controller is always busy and does not come back in idle state. I don't know why buti am pretty sure, it is not sending the data to 24C04 because in "Master Bus Monitor" register i am seeing the SCL and SDA always low. I wasted my whole day to solve the problem but no avail.
Here is the code.

/*
 * main.c
 */

#include "registers_addresses.h"

void Init(void);
void GPIO_PORTF_Init(void);
int main(void) {
	int i;

	/*
	 * Initialization for LED
	*/
	GPIO_PORTF_Init();

	/*
	 * Initialization for PORTB and I2C
	*/
	Init();

	while(1){

		/*
		 * Slave Adress 0b10100000
		*/
		Write(((I2C0_BASE)|(I2CMSA)), (0xA0));

		/*
		 * Memory Address 0x5
		*/
		Write(((I2C0_BASE)|(I2CMDR)), (0x00000005)); // this is address

		/*
		 * Start the communication and run (Start bit and run)
		*/
		Write(((I2C0_BASE)|(I2CMCS)), (0x00000003)); // start and run

		/*
		 * Wait until the controller is not busy
		*/
		while(((Read(((I2C0_BASE)|(I2CMCS))))&0x1)); // run until busy flag is 0

		/*
		 * Check for error
		*/
		if(((Read(((I2C0_BASE)|(I2CMCS))))&0x2)){
			Write(((GPIO_PORTF_BASE)|(DATA)|((1<<1)<<2)), (1<<1)); // if there is error, turn ON the LED
		}
		else{

			Write(((GPIO_PORTF_BASE)|(DATA)|((1<<1)<<2)), ~(1<<1)); // turn OFF the LED

			/*
			 * Insert this data to 0x5 location
			*/
			Write(((I2C0_BASE)|(I2CMDR)), (0x000000FF)); // this is data

			/*
			 * run again and put stop bit at the end
			*/
			Write(((I2C0_BASE)|(I2CMCS)), (0x00000005)); // stop and run

			/*
			 * Wait until the controller is not busy
			*/
			while(((Read(((I2C0_BASE)|(I2CMCS))))&0x1)); // run until busy flag is 0

			/*
			 * Check for errors
			*/
			if(((Read(((I2C0_BASE)|(I2CMCS))))&0x2)){
				Write(((GPIO_PORTF_BASE)|(DATA)|((1<<1)<<2)), (1<<1)); // if there is error, turn ON the LED
			}
			else {
				Write(((GPIO_PORTF_BASE)|(DATA)|((1<<1)<<2)), ~(1<<1)); // turn OFF the LED
			}
		}


		/*
		 * Toggle LED
		*/
		Write(((GPIO_PORTF_BASE)|(DATA)|((1<<1)<<2)), (1<<1));
		for(i=0;i<200000; i++);

		Write(((GPIO_PORTF_BASE)|(DATA)|((1<<1)<<2)), ~(1<<1));
		for(i=0;i<200000; i++);

	}
	return 0;
}

void Init(void){
	/*
	 * Enable Clock for I2C 0 module
	 */
	WritewithOR(((SYS_BASE)|(RCGCI2C)), (1<<0));

	/*
	 * Enable Clock for GPIO PORTB
	*/
	WritewithOR(((SYS_BASE)|(RCGCGPIO)), (1<<1));

	/*
	 * Enable Alternate Functionality for PB2(SCL) and PB3(SDA)
	*/
	WritewithOR(((GPIO_PORTB_BASE)|(AFSEL)), (1<<2)|(1<<3));

	/*
	 * Enable Open Drain for PB3 (SDA)
	*/
	WritewithOR(((GPIO_PORTB_BASE)|(ODR)), (1<<3));

	/*
	 * Select Alternate Functionality I2C0 for PB2 and PB3
	*/
	WritewithOR(((GPIO_PORTB_BASE)|(PCTL)), (0x00003300));

	/*
	 * I2C0 is master device
	*/
	Write(((I2C0_BASE)|(I2CMCR)), (0x00000010));

	/*
	 * Time Period register value
	*/
	Write(((I2C0_BASE)|(I2CMTPR)), (0x00000009));
}

void GPIO_PORTF_Init(void){
	WritewithOR(((SYS_BASE)|(RCGCGPIO)), (1<<5));
	WritewithOR(((GPIO_PORTF_BASE)|(DIR)), (1<<1));
	WritewithOR(((GPIO_PORTF_BASE)|(DEN)), (1<<1));
}

PS: i connected the pull up resistors to SCL and SDA.

 

[milan.rajik]

Tiva is 3.3V device ? If yes, are there pullups on I2C lines ?

 

[hamid159]

yes .. as I above mentioned. I connected the pull up resistors to SCL and SDA.