Content originally posted in LPCWare by Tsuneo on Thu Apr 17 14:17:17 MST 2014 You may send 24bits data (MSB first) with 8bits padding over 32bits word
3.1 Serial Data Serial data is transmitted in two’s complement with the MSB first. The MSB is transmitted first because the transmitter and receiver may have different word lengths. It isn’t necessary for the transmitter to know how many bits the receiver can handle, nor does the receiver need to know how many bits are being transmitted.
When the system word length is greater than the transmitter word length, the word is truncated (least significant data bits are set to '0') for data transmission. If the receiver is sent more bits than its word length, the bits after the LSB are ignored.
