Interfacing a serial DAC
That DAC uses I2C bus.


After every start condition you have to send device address.
The I2C protocol transmits/receives a total of 8 bits (without ACK) thus a byte is transmitted/received. If it has 10 data bits and 4 control bits, then it must use 2 bytes data (16 bits) thus some bits (2) remain unused. They should be set to 0 according to datasheet.
After sending all data bits to the device (register), maximum time required for producing stable output is \$10\mu \$seconds.
You can use the read function to make a simple error check. Write something to the DAC, then read it back and see if it is the same.