User manual

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CHAPTER 3 FEATURES OF THE ARCHITECTURE AND MEMORY MAP
(7) Stack addressing
This addressing mode is used for save/restoration operation in interrupt processing or subroutine
processing.
In this addressing mode, the address indicated by the stack pointer (8 bits) of data memory bank 0 is
specified.
This addressing mode can be used for register save/restoration operation using the PUSH or POP
instruction as well as save/restoration operation in interrupt and subroutine processing.
Examples 1. A register is saved and restored in subroutine processing.
SUB: PUSH XA
PUSH HL
PUSH BS ; Save MBS and RBS
·
·
·
POP BS
POP HL
POP XA
RET
2. The contents of the HL register pair are transferred to the DE register pair.
PUSH HL
POP DE ; DE <– HL
3. A branch is made to the address indicated by the [XABC] register.
PUSH BC
PUSH XA
RET ; Branch to address XABC