Motorola MPC823e Reference Manual page 528

Communication Processor Module
16.4 TIMERS
The communication processor module includes four identical 16-bit general-purpose timers
that can be cascaded into two 32-bit timers. Each general-purpose timer consists of a timer
mode register, a timer capture register, a timer counter, a timer reference register, a timer
event register, and a timer global configuration register. The timer mode register contains
the prescaler value that you program. The timer block diagram is illustrated in Figure 16-34.
TGCR
GLOBAL CONFIGURATION REGISTER
TER1
MODE REGISTER
TMR1
PRESCALER
DIVIDER
TCN1
TIMER COUNTER
TRR1
REFERENCE REGISTER
TCR1
CAPTURE REGISTER
TIMER1
TIMER2
TIMER3
TIMER4
16.4.1 Features
The following list summarizes the main features of the timers:
• Maximum period of 10.7 seconds (at 25MHz)
• Minimum 40ns resolution (at 25MHz)
• Programmable sources for the clock input
• Input capture capability
• Output compare with programmable mode for the output pin
• Four timers can be internally or externally cascaded to form two 32-bit timers. Timer 1
exclusive-Or'ed with SPKR input from PCMCIA to generate SPKROUT
• Free run and restart modes
16-74
GENERAL SYSTEM CLOCK
EVENT REGISTER
MODE BITS
CLOCK
Figure 16-34. Timer Block Diagram
MPC823e REFERENCE MANUAL
TIMER
CLOCK
GENERATOR
CAPTURE
DETECTION
TGATE1
TIN1
TIN2
TIN3
TIN4
TOUT1
TOUT2
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