I'm trying to use the I2C_DRV_MasterXXXDataBlocking parameters and need some clarification. The following is my interpretation and I would like comments for clarification. (My environment is Windows7, KDS, KSDK, PE, and MQX on FRDM-K22F.)
The documentation states (simplified with my annotation):
instance, // Which I2C Bus
device, // Address on I2C bus (7-bit width)
cmdBuff, // If not NULL, commands to be sent
cmdSize, // If not zero, number of bytes sent as command IF cmdBuff is not NULL
// If command was sent, a restart applied
// and I2C Address sent with a READ cycle
rxBuff, // Memory location for data read
rxSize, // Number of bytes to read , unless terminated by device
timeout_ms );// Time out in milliseconds (API states microseconds!)
My question is: If cmdBuff is NULL, does the driver issue a read to the device without sending out the command first? In other words, the restart cycle is never performed.
I have the same question on the I2C_DRV_MasterReadDataBlocking() function as well.
In these cases I would expect to see the I2C bus go immediately into the appropriate transfer. Am I correct in this interpretation?