Chapter 16 Power-On-Clear Circuit; Functions Of Power-On-Clear Circuit - NEC 78K0S/KB1+ User Manual

16.1 Functions of Power-on-Clear Circuit

The power-on-clear circuit (POC) has the following functions.
• Generates internal reset signal at power on.
• Compares supply voltage (V
when V < V .
DD POC
• Compares supply voltage (V
≥ V
when V .
DD POC
Cautions 1. If an internal reset signal is generated in the POC circuit, the reset control flag register
(RESF) is cleared to 00H.
2. Because the detection voltage (V
voltage in the range of 2.2 to 5.5 V.
Remark This product incorporates multiple hardware functions that generate an internal reset signal. A flag that
indicates the reset cause is located in the reset control flag register (RESF) for when an internal reset
signal is generated by the watchdog timer (WDT) or low-voltage-detection (LVI) circuit. RESF is not
cleared to 00H and the flag is set to 1 when an internal reset signal is generated by WDT or LVI.
For details of RESF, see CHAPTER 15 RESET FUNCTION.

CHAPTER 16 POWER-ON-CLEAR CIRCUIT

) and detection voltage (V
DD
) and detection voltage (V
DD
) of the POC circuit is in a range of 2.1 V ±0.1 V, use a
POC
User's Manual U17446EJ3V1UD
= 2.1 V ±0.1 V), and generates internal reset signal
POC
= 2.1 V ±0.1 V), and releases internal reset signal
POC
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