NEC PD75402A - Manual (Page 42)

CHAPTER 4. INTERNAL CPU FUNCTIONS
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The program counter operates as follows.
• Normal operation
The content is incremented automatically according to the number of bytes of the instruction every time one is
executed.
• Branch instruction (BR, BRCB) execution
The immediate data indicating the address of the destination of branching is set in the PC.
• Subroutine call instruction (CALLF) execution and vector interrupt
The content of the PC at that time is saved in the stack memory and then the address of each destination of
branching is set in the PC.
• Return instruction (RET, RETS, RETI) execution
The content of the stack memory is set in the PC.
• RESET input
The low-order 3 bits of the program memory’s address 000H is set in PC10 to PC8 and the content of address
001H is set in PC7 to PC0 and then initialized. It is possible to start the program from any address.
CHAPTER 4. INTERNAL CPU FUNCTIONS
4.1 PROGRAM COUNTER (PC) ..... 11 BITS
An 11-bit binary counter to hold the program memory address information.
Fig. 4-1 Program Counter Configuration
PC10 PC9 PC8 PC7 PC6 PC5 PC4 PC3 PC2 PC1 PC0