Добрый день.
Есть утройство у которого на шине i2c висит 3 слейва, все в приделах одной платы. Часы, ээпром и дисплей. Так вот, основная часть логики завязана с роботой еепром. Программа довольно много обращается к еепром и иногда бывают сбои. Пишу код под Coide и готового решения AN2824 для него я не нашел.
Собственно проблема в том, что если читаю 1 или 2 байта читается какой-то мусор, а если больше 3 то и вовсе виснет еепром и шина всегда занята, даже если перезагружаю i2c на контроллере. С записью проблем нет. DMA не использую так как приходится много читать для поиска пустого блока, проверку делаю "на лету" без выгрузки всего муссора с eeprom в озу. Второй день уже не могу понять в чем проблема, может чего уже не замечаю, вот код.
unsigned char I2C_Read_git(I2C_TypeDef* I2Cx, unsigned char SlaveAddress, unsigned char *buf, unsigned int nbyte){
//I2C2->CR2 |= I2C_IT_ERR; //interrupts for errors
// Wait for idle I2C interface
if(wait_for(FLAG, I2C_FLAG_BUSY) == 0) return I2CERR; //go out with timeout error
// Enable Acknowledgement, clear POS flag
I2C_AcknowledgeConfig(I2Cx, ENABLE);
I2C_NACKPositionConfig(I2Cx, I2C_NACKPosition_Current);
// Intiate Start Sequence (wait for EV5
I2C_GenerateSTART(I2Cx, ENABLE);
if(wait_for(EVENT, I2C_EVENT_MASTER_MODE_SELECT) == 0) return I2CERR; //go out with timeout error
// Send Address
I2C_Send7bitAddress(I2Cx, SlaveAddress, I2C_Direction_Receiver);
// EV6
if(wait_for(FLAG, I2C_FLAG_ADDR) == 0) return I2CERR; //go out with timeout error
if(nbyte == 1){
// Clear Ack bit
I2C_AcknowledgeConfig(I2Cx, DISABLE);
// EV6_1 -- must be atomic -- Clear ADDR, generate STOP
__disable_irq();
(void) I2Cx->SR2;
I2C_GenerateSTOP(I2Cx,ENABLE);
__enable_irq();
// Receive data EV7
if(wait_for(FLAG, I2C_FLAG_RXNE) == 0) return I2CERR; //go out with timeout error
*buf++ = I2C_ReceiveData(I2Cx);
}else if(nbyte == 2){
// Set POS flag
I2C_NACKPositionConfig(I2Cx, I2C_NACKPosition_Next);
// EV6_1 -- must be atomic and in this order
__disable_irq();
(void) I2Cx->SR2; // Clear ADDR flag
I2C_AcknowledgeConfig(I2Cx, DISABLE); // Clear Ack bit
__enable_irq();
// EV7_3 -- Wait for BTF, program stop, read data twice
if(wait_for(FLAG, I2C_FLAG_BTF) == 0) return I2CERR; //go out with timeout error
__disable_irq();
I2C_GenerateSTOP(I2Cx,ENABLE);
*buf++ = I2C_ReceiveData(I2Cx);
__enable_irq();
*buf++ = I2C_ReceiveData(I2Cx);
I2C_NACKPositionConfig(I2Cx, I2C_NACKPosition_Current);
}else{
(void) I2Cx->SR2; // Clear ADDR flag
while (nbyte-- != 3){
// EV7 -- cannot guarantee 1 transfer completion time, wait for BTF
// instead of RXNE
if(wait_for(FLAG, I2C_FLAG_BTF) == 0) return I2CERR; //go out with timeout error
*buf++ = I2C_ReceiveData(I2Cx);
}
if(wait_for(FLAG, I2C_FLAG_BTF) == 0) return I2CERR; //go out with timeout error
// EV7_2 -- Figure 1 has an error, doesn't read N-2 !
I2C_AcknowledgeConfig(I2Cx, DISABLE); // clear ack bit
__disable_irq();
I2C_GenerateSTOP(I2Cx,ENABLE); // program stop
*buf++ = I2C_ReceiveData(I2Cx); // receive byte N-2
__enable_irq();
// wait for byte N
if(wait_for(EVENT, I2C_EVENT_MASTER_BYTE_RECEIVED) == 0) return I2CERR; //go out with timeout error
*buf++ = I2C_ReceiveData(I2Cx); // receive byte N-1
nbyte = 0;
}
// Wait for stop
if(wait_for(FLAG, I2C_FLAG_STOPF) == 0) return I2CERR; //go out with timeout error
I2C_AcknowledgeConfig(I2Cx, ENABLE);
return I2COK;
}
unsigned char EEPROM_Read(unsigned int addr, unsigned char *data, unsigned char len){
unsigned char y=0;
// While the bus is busy
if(wait_for(FLAG, I2C_FLAG_BUSY) == 0) return I2CERR; //go out with timeout error
I2C_AcknowledgeConfig(I2C2, ENABLE);
// Generate the Start Condition
I2C_GenerateSTART(I2C2, ENABLE);
if(wait_for(EVENT, I2C_EVENT_MASTER_MODE_SELECT) == 0) return I2CERR; //go out with timeout error
I2C_Send7bitAddress(I2C2, 0xA0, I2C_Direction_Transmitter); //send adress chip
if(wait_for(EVENT, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED) == 0) return I2CERR; //go out with timeout error
I2C_SendData(I2C2, addr>>8); //send upper bit
if(wait_for(EVENT, I2C_EVENT_MASTER_BYTE_TRANSMITTED) == 0) return I2CERR; //go out with timeout error
I2C_SendData(I2C2, addr & 0xFF); //send lower bit
if(wait_for(EVENT, I2C_EVENT_MASTER_BYTE_TRANSMITTED) == 0) return I2CERR; //go out with timeout error
I2C_GenerateSTOP(I2C2, ENABLE);
if(wait_for(FLAG, I2C_FLAG_BUSY) == 0) return I2CERR; //go out with timeout error
y=I2C_Read_git(I2C2, 0xA0, data, len);
return y;
}
А вот код который работает, но здесь нет всех замечаний которые были написаны в AN2824 о глючном i2c в stm32f1:
unsigned char EEPROM_Read(unsigned int addr, unsigned char *data, unsigned char len){
unsigned int i;
// While the bus is busy
if(wait_for(FLAG, I2C_FLAG_BUSY) == 0) return I2CERR; //go out with timeout error
I2C_AcknowledgeConfig(I2C2, ENABLE);
// Generate the Start Condition
I2C_GenerateSTART(I2C2, ENABLE);
if(wait_for(EVENT, I2C_EVENT_MASTER_MODE_SELECT) == 0) return I2CERR; //go out with timeout error
I2C_Send7bitAddress(I2C2, 0xA0, I2C_Direction_Transmitter); //send adress chip
if(wait_for(EVENT, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED) == 0) return I2CERR; //go out with timeout error
I2C_SendData(I2C2, addr>>8); //send upper bit
if(wait_for(EVENT, I2C_EVENT_MASTER_BYTE_TRANSMITTED) == 0) return I2CERR; //go out with timeout error
I2C_SendData(I2C2, addr & 0xFF); //send lower bit
if(wait_for(EVENT, I2C_EVENT_MASTER_BYTE_TRANSMITTED) == 0) return I2CERR; //go out with timeout error
I2C_GenerateSTOP(I2C2, ENABLE);
if(wait_for(FLAG, I2C_FLAG_BUSY) == 0) return I2CERR; //go out with timeout error
I2C_GenerateSTART(I2C2, ENABLE); // Generate the Start Condition
if(wait_for(EVENT, I2C_EVENT_MASTER_MODE_SELECT) == 0) return I2CERR; //go out with timeout error
I2C_Send7bitAddress(I2C2, 0xA0, I2C_Direction_Receiver); //send adress chip
if(wait_for(EVENT, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED) == 0) return I2CERR; //go out with timeout error
for(i = 0; i<len; i++){
if(i<len-1){
if(wait_for(EVENT, I2C_EVENT_MASTER_BYTE_RECEIVED) == 0) return I2CERR; //go out with timeout error
}else{
I2C_AcknowledgeConfig(I2C2, DISABLE); // Prepare an NACK for the next data received
if(wait_for(EVENT, I2C_EVENT_MASTER_BYTE_RECEIVED) == 0) return I2CERR; //go out with timeout error
I2C_GenerateSTOP(I2C2, ENABLE);
}
*data = I2C_ReceiveData(I2C2);
data++;
}
if(wait_for(FLAG,I2C_FLAG_STOPF)==0) return I2CERR;
I2C_AcknowledgeConfig(I2C2, ENABLE);
//Delay_ms(5);
return I2COK;
}
За ранние спасибо.
