Posted on May 05, 2017 at 11:56Hello ST community,
I had already posted the same query with HAL libraries but I am trying to write and read to/from the EEPROM by using old method but I am stucked in reading from the eeprom.
My code is,
uint8_t mem_adr = 0x01;
uint8_t buf = 5;
uint8_t buf_read;
&sharpdefine I2C_ADDRESS (0x50 << 1)
I2C1_Setup();
//I2C write/* clear CR2 specific bits */
I2C1->CR2 &= (uint32_t)~((uint32_t)(I2C_CR2_SADD | I2C_CR2_NBYTES | I2C_CR2_RELOAD | I2C_CR2_AUTOEND | I2C_CR2_RD_WRN | I2C_CR2_START | I2C_CR2_STOP));
/* update CR2 */
I2C1->CR2 |= (uint32_t)(((uint32_t)I2C_ADDRESS & I2C_CR2_SADD) | (((uint32_t)1 << 16 ) & I2C_CR2_NBYTES) | \
(uint32_t)I2C_CR2_AUTOEND |(uint32_t)I2C_CR2_START| (uint32_t)I2C_CR2_RD_WRN);
I2C1->TXDR = (uint8_t) mem_adr; /* Send Byte address */
__nop();__nop();__nop();__nop();__nop();
I2C1->ISR |= I2C_ISR_TXE;
I2C1->CR2 |= I2C_CR2_AUTOEND;
if((I2C1->ISR & I2C_ISR_TXE)==I2C_ISR_TXE){
I2C1->CR2 |= I2C_CR2_AUTOEND;
I2C1->TXDR = (uint8_t)buf;
I2C1->CR2 |= I2C_CR2_STOP;
}
//I2C read
I2C1->CR2 &= (uint32_t)~((uint32_t)(I2C_CR2_SADD | I2C_CR2_NBYTES | I2C_CR2_RELOAD | I2C_CR2_AUTOEND | I2C_CR2_RD_WRN | I2C_CR2_START | I2C_CR2_STOP));
I2C1->CR2 |= (uint32_t)(((uint32_t)I2C_ADDRESS & I2C_CR2_SADD) | (((uint32_t)1 << 16 ) & I2C_CR2_NBYTES) | \
(uint32_t)I2C_CR2_AUTOEND|(uint32_t)I2C_CR2_START) ;
I2C1->ISR |= I2C_ISR_TXE;
I2C1->TXDR = (uint8_t) mem_adr; // Send Memory address
__nop();__nop();__nop();__nop();__nop();
__nop();__nop();__nop();__nop();__nop();
//Here TC and RXNE are always 0. The problem must be RXNE is not changing its state to read the data
I2C1->CR1|= (uint32_t)(I2C_CR1_RXIE);
I2C1->CR2 |= (uint32_t)((uint32_t)I2C_CR2_RD_WRN |(((uint32_t)I2C_ADDRESS_R & I2C_CR2_SADD)) | (((uint32_t)1 << 16 ) & I2C_CR2_NBYTES) );
// As RXNE is 0 program is unable to enter this loop
if((I2C1->ISR & I2C_ISR_RXNE)==I2C_ISR_RXNE){
buf_read = I2C1->RXDR;
}
Could anyone please tell me where is the mistake?
Thank you in advance.
Regards,
Mandar.
#eeprom #stm32f0-i2c
