33.3.3.3 LD - Load Data from Data Space Using Indirect Addressing

The LD instruction is used to load data form the bus matrix and into the serial shift register for serial read out. The LD instruction is based on indirect addressing, which means that the address pointer in the UPDI needs to be written prior to bus matrix access. Automatic pointer post increment operation is supported, and is useful when the LD instruction is used with REPEAT. It is also possible to do a LD of the UPDI pointer register. Maximum supported size for address and data load is 16 bit.

The Figure above shows an example of a typical LD sequence, where data is received after the Guard Time period. Loading data from the UPDI pointer register follows the same transmission protocol.