mc68hc11d0cfn2 Freescale Semiconductor, Inc, mc68hc11d0cfn2 Datasheet - Page 115

• Manufacturer Part Number: mc68hc11d0cfn2
• Description: M68hc11 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

8.7.2 Pulse Accumulator Count Register
8.7.3 Pulse Accumulator Status and Interrupt Bits
MC68HC711D3 — Rev. 2
MOTOROLA
PEDGE — Pulse Accumulator Edge Control Bit
DDRA3 — Data Direction Register for Port A Bit 3
I4/O5 — Input Capture 4/Output Compare 5 Bit
RTR1 and RTR0 — RTI Interrupt Rate Select Bits
The 8-bit read/write pulse accumulator count register (PACNT) contains the count
of external input events at the PAI input or the accumulated count. The counter is
not affected by reset and can be read or written at any time. Counting is
synchronized to the internal PH2 clock so that incrementing and reading occur
during opposite half cycles.
The pulse accumulator control bits, PAOVI and PAII, PAOVF, and PAIF are located
within timer registers TMSK2 and TFLG2.
PAOVI and PAOVF — Pulse Accumulator Interrupt Enable and Overflow Flag
Address:
This bit has different meanings depending on the state of the PAMOD bit, as
shown in
Refer to
Refer to
Refer to
The PAOVF status bit is set each time the pulse accumulator count rolls over
from $FF to $00. To clear this status bit, write a 1 in the corresponding data bit
position (bit 5) of the TFLG2 register. The PAOVI control bit allows configuring
the pulse accumulator overflow for polled or interrupt-driven operation and does
Reset:
Read:
Write:
Freescale Semiconductor, Inc.
For More Information On This Product,
Figure 8-21. Pulse Accumulator Count Register (PACNT)
$0027
Section 5. Input/Output (I/O)
8.3 Input
8.5 Real-Time
Bit 7
Bit 7
PAMOD
Table
0
0
1
1
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Table 8-8. Pulse Accumulator Edge Control
8-8.
Bit 6
Programmable Timer
Capture.
PEDGE
6
0
1
0
1
Interrupt.
Bit 5
PAI falling edge increments the counter.
PAI rising edge increments the counter.
A 0 on PAI inhibits counting.
A 1 on PAI inhibits counting.
5
Unaffected by reset
Bit 4
4
Ports.
Action on Clock
Bit 3
3
Bit 2
2
Programmable Timer
Pulse Accumulator
Bit 1
1
Data Sheet
Bit 0
Bit 0
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