Rainbow-electronics AT89C5122 Manual de usuario descargar pdf (Pagina 176)

176

AT8xC5122/23

4202E–SCR–06/06

Reset Controlled by an

External Superviser Device

As the reset pin can be forced in output by the Watch-Dog timer (WDT) or the POR/PFD

features, there can be a conflict between the external superviser device and the micro-

controller’s reset pin when in one side the external superviser is pulling the reset pin to

VCC and in another side the WDT or POR/PFD features tries to force the reset pin to

ground. Therefore, it recommended to insert a series resistor of 1.8K +/-10% or a diode

(1N4148 for instance) between the external superviser device and the reset pin as

detailed in the following figures.

Figure 106. Use of an External Serial Resistor

Figure 107. Use of an External Diode

RST

Vcc

10 K

Microcontrolleur

1.8 K

Superviser

device

To other on-board

circuitry

Power Fail

Detector

Watchdog

Timer

Power On

Reset

RST

Vcc

10 K

Microcontrolleur

Superviser

device

To other on-board

circuitry

Power Fail

Detector

Watchdog

Timer

Power On

Reset

1N4148

1 2 ... 171 172 173 174 175 176 177 178 179 180 181 ... 212 213

Comentarios a estos manuales

Sin comentarios

Rainbow-electronics AT89C5122 Manual de usuario Pagina 176

Comentarios a estos manuales

Relacionado con productos y manuales para Software Rainbow-electronics AT89C5122