HP 9000 Series 743, Service Handbook, Page: 56 / 165

Functional Description
Battery Backed Real-Time Clock
2-26
Interval Timers
The VME Controller ASIC includes two interval timers and a watchdog timer. These tim-
ers provide interrupt on terminal count and interrupt and restart on terminal count capabil-
ity. Table 2-20 lists the interval timer specifications.
Watchdog Timer
The VME controller ASIC also includes a watchdog timer. When enabled, the watchdog
timer generates at service mode after 256 ms, if not reset by software. If the software does
not reset it, then it generates a hardware reset.
Table 2-20 Interval Timer Specifications
Timer 1 Length 32 bits, cascadeable into timer 2
Timer 2 Length 16 bits, cascadeable into timer 3
Timer 3 Length 16 bits