Timer - Motorola DragonBall MC68328 User Manual

SECTION 6

TIMER

The MC68328 processor contains two identical general-purpose 16-bit timers with a pro-
grammable prescaler and a software watchdog timer. Figure 6-1 shows the block diagram
of the time module.
CONTROL REGISTER
PRESCALAR REGISTER
EVENT REGISTER
COMPARE REGISTER
COUNTER REGISTER
CAPTURE REGISTER
The key features of the timers include:
• Maximum period of 524 seconds (at 32kHz)
• 240-ns resolution (at 16.67 MHz)
• Programmable sources for the clock input, including external clock
• Input capture capability with programmable trigger edge on input pins
• Output compare with programmable mode for the output pins
• Cascading timers for constructing one 32-bit timer
• Free run and restart modes
The software watchdog timer has the following features:
• 16-bit counter and reference register
• Maximum period of 16.38 seconds
MOTOROLA
TIMER
CLOCK
Figure 6-1. Timer Block Diagram
MC68328 DRAGONBALL PROCESSOR USER'S MANUAL
DID 16
PRESCALE
CLOCK GENERATOR
CAPTURE
DETECT
SYSTEM CLOCK
32K HZ CLOCK
TIN
INTERRUPT
MPU BUS
TOUT
6-1