Overall Configuration of the CPU: CPU Core (1)

PSW (Program Status Word)
A register that holds the operation results and the state of the instruction execution result.
It consists of various flags.

General-purpose Register
A storage circuit that stores the data.
General-purpose registers are called W, A, B, C, D, E, H, L, etc. depending on the location of the storage circuit.
A place where the calculation result is stored is called an accumulator. Ten registers of W, A, B, C, D, E, H, L, IX, and IY have the accumulator roles in the TLCS-870/C1.

Program counter (PC)
A storage circuit that stores a memory address to read instructions.