The data path of a simple CPU is shown in figure in the next page. In the data path shown, the $$1,$ S$2$ and D fields in the instruction represent the two source and one destination operands, and are directly connected to the address port of the register file. Register S$1$ will be read into RFOUT$1,$ while register S$2$ will be read into RFOUTZ$2.$ RFIN will be written into register D$.$ Registers A and B are the input registers and C the output register of the ALU. There is a single CPU bus in the data path.