UPD784938 Datasheet, PDF (91/733 Pages) NEC – 16-Bit Single-Chip Microcontrollers

CHAPTER 3 CPU ARCHITECTURE
Cautions 1. With stack addressing, the entire 1-Mbyte space can be accessed but a stack area cannot be reserved
in the SFR area or internal ROM area.
2. The stack pointer (SP) is undefined after RESET input. Moreover, non-maskable interrupts can still
be acknowledged when the SP is in an undefined state. An unanticipated operation may therefore be
performed if a non-maskable interrupt request is generated when the SP is in the undefined state
directly after reset release. To avoid this risk, the program after reset release must be written as
follows.
RSTVCT CSEG AT 0
DW RSTSTRT
to
INITSEG CSEG BASE
RSTSTRT : LOCATION 0H ; or LOCATION 0FH
MOVG SP, #STKBGN
Preliminary User’s Manual U13987EJ1V0UM00
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