Program Counter (Pc) - Fujitsu F2MC-16LX Hardware Manual

2.3.4

Program Counter (PC)

The function of program counter (PC) is explained.
Program Counter (PC)
The PC is a 16-bit counter to indicate the lower 16 bits of memory address of the instruction code to be
executed by the CPU. The upper 8-bit address is indicated by the program bank register (PCB). The PC
content is updated by the conditional branch instruction, the subroutine call instruction, the interrupt, the
reset, etc. In addition, it can be used as the base pointer at the operand access.
Figure 2.3-10 shows the function of the program counter (PC).
PCB
FE
H
Note:
Neither PC nor PCB can be directly rewritten by program (e.g. by a MOV PC, #FF instruction)
Figure 2.3-10 Function of Program Counter (PC)
PC ABCD
H
Next execution instruction
FEABCD
H
CHAPTER 2 CPU
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