Motorola MC68VZ328 - Manual (Page 211)

Real-Time Clock 11-1
Chapter 11
Real-Time Clock
This chapter describes the real-time clock (RTC) module, which is composed of six blocks as shown in
Figure 11-1: the prescaler, time-of-day (TOD) clock, TOD alarm, programmable real-time interrupt,
watchdog timer, and minute stopwatch, as well as control registers and bus interface hardware. The RTC
module can generate three different level 4 interrupts to the interrupt controller. The RTC can also generate
a watchdog system reset. The following sections describe how each block operates and interacts with other
modules in both the RTC and the MC68VZ328.
Figure 11-1. Real-Time Clock Module Simplified Block Diagram
Real-Time Interrupt
Real-Time
Interrupt
Prescaler
Control
Registers
RTC Interrupt
Watchdog Interrupt
Watchdog Reset
1 Pulse
per
Second
Watchdog Timer
Minute Stopwatch
TOD Alarm & Comparator
TOD Clock
CLK32
Second
Counter
1 Pulse
per
Minute
1 Pulse
per
Hour
1 Pulse
per
Day
Minute
Counter
Hour
Counter
Day
Counter