MC68HC705J MOTOROLA [Motorola, Inc], MC68HC705J Datasheet - Page 111

• Manufacturer Part Number: MC68HC705J
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

9.3 Operation
MC68HC705J1A — Rev. 4.0
MOTOROLA
Addr.
$0008
$0009
Timer Status and Control
Timer Counter Register
Register Name
Register (TSCR)
See page 112.
See page 114.
(TCR)
A 15-stage ripple counter, preceded by a prescaler that divides the
internal clock signal by four, provides the timing reference for the timer
functions. The value of the first eight timer stages can be read at any
time by accessing the timer counter register at address $0009. A timer
overflow function at the eighth stage allows a timer interrupt every 1024
internal clock cycles.
The next four stages lead to the real-time interrupt (RTI) circuit. The RT1
and RT0 bits in the timer status and control register at address $0008
allow a timer interrupt every 16,384, 32,768, 65,536, or 131,072 clock
cycles. The last four stages drive the selectable COP system. For
information on the COP, refer to the
Properly (COP)
Reset:
Reset:
Read:
Read:
Write:
Write:
Figure 9-2. I/O Register Summary
Bit 7
TMR7
TOF
0
0
Multifunction Timer Module
= Unimplemented
TMR6
RTIF
Module.
6
0
0
TMR5
TOIE
5
0
0
TMR4
RTIE
4
0
0
Section 7. Computer Operating
TOFR
TMR3
3
0
0
0
Multifunction Timer Module
RTIFR
TMR2
2
0
0
0
TMR1
RT1
1
1
0
Technical Data
Operation
TMR0
Bit 0
RT0
1
0
111