PD17012_15 Datasheet, PDF (40/320 Pages) Renesas Technology Corp – 4-BIT SINGLE-CHIP MICROCONTROLLERS WITH DIGITAL TUNING SYSTEM HARDWARE

µPD17012, 17P012
4.4 Notes on Using Data Memory
4.4.1 On power-on reset
The contents of the general-purpose data memory are undefined on power-on reset.
Initialize the general-purpose data memory as necessary.
4.4.2 Notes on unallocated data memory
If a data memory manipulation instruction is executed to a data memory address to which nothing has been
allocated, the following operations are performed.
(1) Device operation
If a read instruction is executed, 0 is read.
Nothing is affected even if a write instruction is executed.
(2) Assembler (RA17K) operation
Assembly is performed normally.
An error does not occur.
(3) In-circuit emulator (IE-17K) operation
If a read instruction is executed, 0 is read.
Nothing is affected even if a write instruction is executed.
An error does not occur.
38
Data Sheet U10101EJ4V0DS