1.2.21.62 1.3.25.62 1.4.21.62 1.5.25.62 1.6.22.62 1.7.23.62 1.9.19.62 1.29.23.62 1.30.18.62 1.31.18.62 1.32.26.62 1.33.16.62 1.37.18.62 1.38.21.62 1.39.18.62 1.40.20.62 SERCOMx_I2C_TransferDirGet Function
C
/* x = SERCOM instance number */
/* I2C slave mode */
SERCOM_I2C_SLAVE_TRANSFER_DIR SERCOMx_I2C_TransferDirGet(void)
Summary
Returns the I2C transfer direction
Description
This function returns the I2C transfer direction
Precondition
SERCOMx_I2C_Initialize must have been called for the associated SERCOM I2C instance
Parameters
None.
Returns
SERCOM_I2C_SLAVE_TRANSFER_DIR_WRITE - I2C master is writing data to I2C slave
SERCOM_I2C_SLAVE_TRANSFER_DIR_READ - I2C master is reading data from I2C slave
Example
The below code snippet shows the use of the SERCOMx_I2C_TransferDirGet() API when SERCOM I2C slave PLIB is used in polled mode (interrupt is disabled).
static bool isFirstByteSent; static bool transferDir; SERCOM_I2C_SLAVE_INTFLAG intFlags = SERCOM0_I2C_InterruptFlagsGet(); if (intFlags & SERCOM_I2C_SLAVE_INTFLAG_AMATCH) { isFirstByteSent = false; // Read and save the transfer direction in a global variable. transferDir = SERCOM0_I2C_TransferDirGet(); // Send ACK succeeded by reception of next byte SERCOM0_I2C_SendCommand(SERCOM_I2C_SLAVE_COMMAND_SEND_ACK); } else if (intFlags & SERCOM_I2C_SLAVE_INTFLAG_DRDY) { if (transferDir == SERCOM_I2C_SLAVE_TRANSFER_DIR_WRITE) { // I2C master is writing data to I2C slave. Read the received byte. rxByte = SERCOM0_I2C_ReadByte(); // Execute acknowledge action succeeded by reception of next byte SERCOM0_I2C_SendCommand(SERCOM_I2C_SLAVE_COMMAND_SEND_ACK); } else { // I2C master is reading data from I2C slave. Check if the previous data // is acknowledged by the I2C master. if (isFirstByteSent == false) { SERCOM0_I2C_WriteByte(txData); isFirstByteSent = true; } else { if (SERCOM0_I2C_LastByteAckStatusGet() == SERCOM_I2C_SLAVE_ACK_STATUS_RECEIVED_ACK) { // Last byte was acknowledged by the I2C master; send another byte. SERCOM0_I2C_WriteByte(txData); //Execute a byte read operation followed by ACK/NACK reception SERCOM0_I2C_SendCommand(SERCOM_I2C_SLAVE_COMMAND_RECEIVE_ACK_NAK); } else { // Last byte was NAK'd by the I2C master; wait for start condition. //Wait for any start (S/Sr) condition SERCOM0_I2C_SendCommand(SERCOM_I2C_SLAVE_COMMAND_WAIT_FOR_START); } } } }
Remarks
None.