Real-Time Clock; Figure 11-1 Real-Time Clock Module Simplified Block Diagram - Motorola MC68VZ328 User Manual

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.
TOD Clock
CLK32
1 Pulse 1 Pulse 1 Pulse 1 Pulse
per per per per
Second Minute Hour Day
Real-Time
Prescaler
Interrupt
Second Minute Hour Day
Counter Counter Counter Counter
Real-Time Interrupt
TOD Alarm & Comparator
RTC Interrupt
Control
Registers
Watchdog Timer
Watchdog Interrupt
Watchdog Reset
Minute Stopwatch
Figure 11-1. Real-Time Clock Module Simplified Block Diagram
Real-Time Clock 11-1