GMS87C1102 Datasheet, PDF (28/80 Pages) Hynix Semiconductor – CMOS SINGLE-CHIP 8-BIT MICROCONTROLLER

GMS87C1102 / GMS87C1202
HYUNDAI MicroElectronics
Stack Area
The stack provides the area where the return address is
saved before a jump is performed during the processing
routine at the execution of a subroutine call instruction or
the acceptance of an interrupt.
When returning from the processing routine, executing the
subroutine return instruction [RET] restores the contents of
the program counter from the stack; executing the interrupt
return instruction [RETI] restores the contents of the pro-
gram counter and flags.
The save/restore locations in the stack are determined by
the stack pointed (SP). The SP is automatically decreased
after the saving, and increased before the restoring. This
means the value of the SP indicates the stack location
number for the next save.
28
Oct. 1999 ver 1.0