SN8P2711A
8-Bit Micro-Controller
SONiX TECHNOLOGY CO., LTD
Page 35
Version 0.1
2.3 STACK
OPERATION
2.3.1 OVERVIEW
The stack buffer has 4-level. These buffers are designed to push and pop up program counter’s (PC) data when
interrupt service routine and “CALL” instruction are executed. The STKP register is a pointer designed to point active
level in order to push or pop up data from stack buffer. The STKnH and STKnL are the stack buffers to store program
counter (PC) data.
RET /
RETI
CALL /
INTERRUPT
STKP = 3
STKP = 2
STKP = 1
STKP = 0
STACK Level
STK3H
STK2H
STK1H
STK0H
STACK Buffer
High Byte
PCH
STKP
STK3L
STK2L
STK1L
STK0L
STACK Buffer
Low Byte
PCL
STKP
STKP - 1
STKP + 1