mc68hc11k4vfu4 Freescale Semiconductor, Inc, mc68hc11k4vfu4 Datasheet - Page 71

• Manufacturer Part Number: mc68hc11k4vfu4
• Description: 8-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

11 Pulse Accumulator
M68HC11 K Series
MC68HC11KTS/D
PA7/
PAI/
OC1
(FROM MAIN TIMER)
PIN
M68HC11 K-series MCUs have an 8-bit counter that can be configured as a simple event counter or for
gated time accumulation. The counter can be read or written at any time.
The port A bit 7 I/O pin can be configured to act as a clock in event counting mode, or as a gate signal
to enable a free-running clock (E divided by 64) to the 8-bit counter in gated time accumulation mode.
MAIN TIMER
E 64 CLOCK
Overflow —
Cycle Time
CPU Clock
1 Count —
DDRA7
FROM
FROM
OC1
OUTPUT
BUFFER
EDGE DETECTOR
INPUT BUFFER
Figure 18 Pulse Accumulator System Block Diagram
AND
(2
(2
(1/E)
(E)
14
6
/E)
TMSK2 INT ENABLES
/E)
PACTL CONTROL
Pulse Accumulator (Gated Mode)
DATA BUS
8.192 ms
8.0 MHz
2.0 MHz
MUX
32.0 s
2:1
500 ns
INTERNAL
DATA BUS
Common XTAL Frequencies
PAI EDGE
PAEN
PAEN
CLOCK
12.0 MHz
5.461 ms
21.33 s
3.0 MHz
333 ns
TFLG2 INTERRUPT STATUS
OVERFLOW
ENABLE
PACNT 8-BIT COUNTER
PAOVI
PAOVF
PAII
PAIF
DISABLE
FLAG SETTING
16.0 MHz
4.096 ms
4.0 MHz
16.0 s
250 ns
MOTOROLA
INTERRUPT
REQUESTS
1
2
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