we are not showing the details of the DM circuitry. Fig- ure
Reset Circuitry
Figure 4-2 illustrates the Reset circuitry in more detail. The normal and Reset logic are shown in the diagram.
IC7C70 is the Reset IC. A Low from pin 1 resets the TV µPC. IC7C70 is a Watch Dog type of Reset IC that monitors the µPC’s operation. It has an internal counter that is continually reset by pulses from the µPC, input at pin 4 of the IC. If the µPC locks up, no pulses are generated. The counter reaches its maximum count and a reset pulse is output at pin 1 to reset the µPC.
