WDT

Sample List

This chapter introduces the details of the WDT sample. The RTL87x2G provides the following samples for the WDT peripheral.

• Watch Dog Timer

Functional Overview

The WDT is used to detect the occurrence of a software fault, usually generated by external interference or by unforeseen logical conditions, which causes the application program to abandon its normal sequence. The watchdog circuit generates a MCU reset or a WDT interrupt on the expiry of a programmed time period, unless the program refreshes the contents of the watchdog timer counter before it overflows.

RTL87x2G supports AON WDT. Compared to CORE WDT, AON WDT can continue counting in low power mode. But AON WDT does not support interrupt mode for debug.

Feature List

• Support lv0 and lv1 reset mode.

• Support interrupt mode. (Only CORE WDT)

• 32kHz Clock Source.

Reset Mode

The watchdog circuit generates a MCU reset on the expiry of a programmed time period, unless the program refreshes the watchdog. Reset mode includes two modes:

• Reset lv0: system reset with some special AON registers retention.

• Reset lv1: lv1 reset is a subset of lv0 reset. Except for the AON registers retention in lv0, additional AON registers are retained in lv1 reset.