General-Purpose Registers; Data Saved To The Stack Area; Data Restored From The Stack Area - NEC PD78212 User Manual

8-bit single-chip microcomputer sub-series

Table of Contents

PUSH rp instruction

POP rp instruction

Cautions 1. In stack addressing, the entire 64K bytes can be accessed. A stack area cannot be mapped in the SFR area or internal ROM area.

2. The SP becomes undefined when RESET is input. Meanwhile, nonmaskable interrupts can be acknowledged immediately after

a reset is released. If a nonmaskable interrupt request occurs, while the SP is undefined, immediately after a reset is released,

an unpredictable operation may be carried out. To minimize this danger, initialize the SP immediately after a reset is released.

For details, see Section 12.3.2.

3.2.4 General-Purpose Registers

(1) Configuration

General-purpose registers are mapped to special addresses (0FEE0H to 0FEFFH) in data memory. The

registers are grouped into four banks, each of which consists of eight 8-bit registers (X, A, C, B, E, D, L, H) (see

Fig. 3-9 Data Saved to the Stack Area

CALL, CALLF, and CALLT instructions

Fig. 3-10 Data Restored from the Stack Area

RET instruction

Chapter 3 CPU Function

RETI instruction