The digital window watchdog timer， Atmel? ATA5021， is designed in Atmel’s state-of-the-art 0.8μm SOI technology SMART-I.S.?1. In applications where safety is critical， it is especially important to monitor the microcontroller. Normal microcontroller operation is indicated by a cyclically transmitted trigger signal， which is received by a window watchdog timer within a defined time window. A missing or a wrong trigger signal causes the watchdog timer to reset the microcontroller. The IC is tailored for microcontrollers， which can work in both full-power and sleep mode. With an additional voltage monitoring （power-on reset and supply voltage drop reset）， the Atmel ATA5021 offers a complete monitoring solution for micro-systems in automotive and industrial applications.