MC68HC11KA Motorola, MC68HC11KA Datasheet - Page 52

• Manufacturer Part Number: MC68HC11KA
• Description: 8-Bit Microcontroller
• Manufacturer: Motorola

10 Main Timer
52
MOTOROLA
Time-out Tolerance
The timing system is based on a free-running 16-bit counter with a four-stage programmable prescaler.
A timer overflow function allows software to extend the system's timing capability beyond the counter's
16-bit range.
The timer has three channels of input capture, four channels of output compare, and one channel that
can be configured as a fourth input capture or a fifth output compare. In addition, the timing system in-
cludes pulse accumulator and real-time interrupt (RTI) functions, as well as a clock monitor function,
which can be used to detect clock failures that are not detected by the COP.
Refer to 11 Pulse Accumulator and 10.1 Real-Time Interrupt for further information about these func-
tions. Refer to the following table for a summary of the crystal-related frequencies and periods.
(–0 ms/+...)
overflow —
overflow —
overflow —
overflow —
1 count —
1 count —
1 count —
1 count —
RTR[1:0]
Control
CR[1:0]
PR[1:0]
Bits
0 0
0 1
1 0
1 1
0 0
0 1
1 0
1 1
0 0
0 1
1 0
1 1
131.07 ms
262.14 ms
524.29 ms
32.768 ms
16.384 ms
32.768 ms
16.384 ms
65.536 ms
262.14 ms
4.096 ms
8.192 ms
8.0 MHz
2.0 MHz
16.4 ms
1.049 s
500 ns
500 ns
2.0 s
4.0 s
8.0 s
Table 9 Timer Summary
XTAL Frequencies
21.845 ms
87.381 ms
174.76 ms
349.52 ms
10.923 ms
21.845 ms
COP Watchdog Time-out Rates
10.923 ms
43.691 ms
174.76 ms
699.05 ms
12.0 MHz
2.731 ms
5.461 ms
Periodic (RTI) Interrupt Rates
1.333 s
2.667 s
5.333 s
3.0 MHz
10.9 ms
333 ns
333 ns
Main Timer Count Rates
16.384 ms
65.536 ms
131.07 ms
262.14 ms
16.384 ms
32.768 ms
131.07 ms
524.28 ms
16.0 MHz
2.048 ms
4.096 ms
8.192 ms
8.192 ms
8.192 ms
4.0 MHz
250 ns
250 ns
1.0 s
2.0 s
4.0 s
MC68HC11KA4TS/D
Other Rates
MC68HC11KA4
(E/2
(E/2
(E/2
(E/2
(E/2
(E/2
(E/2
(E/2
(E/2
(E/2
(E/2
(E/16)
(E/214
(E/217
(1/E)
(E/1)
(E/4)
(E/8)
(E)
18
19
20
15
16
19
21
15
16)
13)
15)
)
)
)
)
)
)
)
)
)
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