Power-On-Clear Circuit Control Registers - NEC PD789860 User Manual

11.3 Power-on-Clear Circuit Control Registers

The following three registers control the power-on-clear circuits.
• Power-on-clear register 1 (POCF1)
• Low-voltage detection register 1 (LVIF1)
• Low-voltage detection level selection register 1 (LVIS1)
(1) Power-on-clear register 1 (POCF1)
POCF1 controls POC circuit operation.
This register is set with a 1-bit or 8-bit memory manipulation instruction.
Symbol 7 6
POCF1 0 0
POCOF1
0 Non-generation of reset signal by POC or in cleared state due to a write operation to POCF1
1 Generation of reset signal by POC
POCMK1
0 Generation of reset signal by POC enabled
1 Generation of reset signal by POC disabled
POCMK0
0 POC operating
1 POC halted
Note This value is 04H only after a power-on-clear reset.
Caution For mask ROM versions, POCMK0 and POCMK1 are only valid when the POC switching
circuit has been selected using a mask option.
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CHAPTER 11 POWER-ON-CLEAR CIRCUITS
Figure 11-3. Format of Power-on-Clear Register 1
5 4 3
0 0 0
POC output detection flag
POC operation control
User's Manual U14826EJ5V0UD
<2> <1> <0>
POCOF1 POCMK1 POCMK0
POC reset control
Address After reset R/W
Note
FFDDH 00H R/W