Status I2C_Write(I2C_TypeDef* I2Cx, const uint8_t* buf, uint32_t nbyte, uint8_t SlaveAddress)
{
__IO uint32_t Timeout = 0;
/* Enable Error IT (used in all modes: DMA, Polling and Interrupts */
// I2Cx->CR2 |= I2C_IT_ERR;
if (nbyte)
{
Timed(I2C_GetFlagStatus(I2Cx, I2C_FLAG_BUSY));
// Intiate Start Sequence
I2C_GenerateSTART(I2Cx, ENABLE);
Timed(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_MODE_SELECT));
// Send Address EV5
I2C_Send7bitAddress(I2Cx, SlaveAddress, I2C_Direction_Transmitter);
//Timed(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
// EV6
// Write first byte EV8_1
I2C_SendData(I2Cx, *buf++);
while (--nbyte) {
// wait on BTF
//Timed(!I2C_GetFlagStatus(I2Cx, I2C_FLAG_BTF));
I2C_SendData(I2Cx, *buf++);
}
//Timed(!I2C_GetFlagStatus(I2Cx, I2C_FLAG_BTF));
I2C_GenerateSTOP(I2Cx, ENABLE);
//Timed(I2C_GetFlagStatus(I2C1, I2C_FLAG_STOPF));
}
return Success;
errReturn:
return Error;
}
Status I2C_Read(I2C_TypeDef* I2Cx, uint8_t *buf,uint32_t nbyte, uint8_t SlaveAddress)
{
__IO uint32_t Timeout = 0;
// I2Cx->CR2 |= I2C_IT_ERR; interrupts for errors
if (!nbyte)
return Success;
// Wait for idle I2C interface
Timed(I2C_GetFlagStatus(I2Cx, I2C_FLAG_BUSY));
// 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);
Timed(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_MODE_SELECT));
// Send Address
I2C_Send7bitAddress(I2Cx, SlaveAddress, I2C_Direction_Receiver);
// EV6
Timed(!I2C_GetFlagStatus(I2Cx, I2C_FLAG_ADDR));
if (nbyte == 1) {
// Clear Ack bit
I2C_AcknowledgeConfig(I2Cx, DISABLE);
// EV6_1 -- must be atomic -- Clear ADDR, generate STOP
(void) I2Cx->SR2;
I2C_GenerateSTOP(I2Cx,ENABLE);
// Receive data EV7
Timed(!I2C_GetFlagStatus(I2Cx, I2C_FLAG_RXNE));
*buf++ = I2C_ReceiveData(I2Cx);
}
else if (nbyte == 2) {
// EV6_1 -- must be atomic and in this order
(void) I2Cx->SR2; // Clear ADDR flag
I2C_AcknowledgeConfig(I2Cx, DISABLE); // Clear Ack bit
// EV7_3 -- Wait for BTF, program stop, read data twice
Timed(!I2C_GetFlagStatus(I2Cx, I2C_FLAG_BTF));
I2C_GenerateSTOP(I2Cx,ENABLE);
*buf++ = I2Cx->DR;
*buf++ = I2Cx->DR;
}
else {
(void) I2Cx->SR2; // Clear ADDR flag
while (nbyte-- != 3)
{
// EV7 -- cannot guarantee 1 transfer completion time, wait for BTF
// instead of RXNE
Timed(!I2C_GetFlagStatus(I2Cx, I2C_FLAG_BTF));
*buf++ = I2C_ReceiveData(I2Cx);
}
Timed(!I2C_GetFlagStatus(I2Cx, I2C_FLAG_BTF));
// EV7_2 -- Figure 1 has an error, doesn't read N-2 !
I2C_AcknowledgeConfig(I2Cx, DISABLE); // clear ack bit
*buf++ = I2C_ReceiveData(I2Cx); // receive byte N-2
I2C_GenerateSTOP(I2Cx,ENABLE); // program stop
*buf++ = I2C_ReceiveData(I2Cx); // receive byte N-1
// wait for byte N
Timed(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_RECEIVED));
*buf++ = I2C_ReceiveData(I2Cx);
nbyte = 0;
}
// Wait for stop
Timed(I2C_GetFlagStatus(I2Cx, I2C_FLAG_STOPF));
return Success;
errReturn:
// Any cleanup here
return Error;
}
