UPD17073 NEC, UPD17073 Datasheet - Page 31

• Manufacturer Part Number: UPD17073
• Description: 4-BIT SINGLE-CHIP MICROCONTROLLER WITH HARDWARE FOR DIGITAL TUNING SYSTEM
• Manufacturer: NEC

4.4 Notes on Using Data Memory
4.4.1 On power-ON reset
4.4.2 Notes on data memory not provided
the following operations are performed:
(1) Device operation
(2) Assembler operation
(3) In-circuit emulator operation
On power-ON reset, the contents of the general-purpose data memory are “undefined”.
Initialize the memory if necessary.
If a data memory manipulation instruction is executed to manipulate an address where no data memory is assigned,
When a read instruction is executed, “0” is read.
Nothing is changed even when a write instruction is executed.
Address 40H of BANK1, bit 3 of address 50H, and address 73H are test mode areas. Do not write “1” to these
areas.
The program is assembled normally. No “error” occurs.
“0” is read when a read instruction is executed.
Nothing is changed when a write instruction is executed.
No “error” occurs.
PD17072,17073
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