33.3.3.6 STCS (Store Data to Control and Status register space)
The STCS instruction is used to store data to the UPDI and ASI CS-space. STCS is based on direct addressing, where the address is part of the instruction opcode. The total address space for STCS is 16 byte, and can only access the internal UPDI register space. This instruction only supports byte access, and data size is not configurable.
Figure 33-14 shows the data frame transmitted after the SYNCH and instruction frames. There is no response generated from the STCS instruction, as is the case for ST and STS.