SN8F27E64KB datasheet(49/192 Pages) SONIX

49 / 192 page

SN8F27E60 Series

8-Bit Flash Micro-Controller with Embedded ICE and ISP

SONiX TECHNOLOGY CO., LTD

Page 49

Version 1.4

3.5 EXTERNAL RESET

External reset function is controlled by

“Reset_Pin” code option. Set the code option as “Reset” option to enable

external reset function. External reset pin is Schmitt Trigger structure and low level active. The system is running when

reset pin is high level voltage input. The reset pin receives the low voltage and the system is reset. The external reset

operation actives in power on and normal running mode. During system power-up, the external reset pin must be high

level input, or the system keeps in reset status. External reset sequence is as following.



External reset (only external reset pin enable): System checks external reset pin status. If external reset pin is

not high level, the system keeps reset status and waits external reset pin released.



System initialization: All system registers is set as initial conditions and system is ready.



Oscillator warm up: Oscillator operation is successfully and supply to system clock.



Program executing: Power on sequence is finished and program executes from ORG 0.

The external reset can reset the system during power on duration, and good external reset circuit can protect the

system to avoid working at unusual power condition, e.g. brown out reset in AC power application

…

3.6 EXTERNAL RESET CIRCUIT

3.6.1 Simply RC Reset Circuit

MCU

VDD

VSS

VCC

GND

RST

47K ohm

0.1uF

100 ohm

This is the basic reset circuit, and only includes R1 and C1. The RC circuit operation makes a slow rising signal into

reset pin as power up. The reset signal is slower than VDD power up timing, and system occurs a power on signal from

the timing difference.



Note: The reset circuit is no any protection against unusual power or brown out reset.

SN8F27E64KB Datasheet(PDF) 49 Page - SONiX Technology Company