MC68HCP11 Datasheet, PDF (37/45 Pages) Motorola, Inc – 8-Bit Microcontroller

PR[1:0]
00
01
10
11
Prescaler
1
4
8
16
TFLG2 — Timer Interrupt Flag 2
Bit 7
6
5
4
3
2
1
TOF
RTIF PAOVF PAIF
0
0
0
RESET:
0
0
0
0
0
0
0
Clear flags by writing a one to the corresponding bit position(s).
$1025
Bit 0
0
0
TOF — Timer Overflow Flag
Set when TCNT changes from $FFFF to $0000.
RTIF — Real-Time (Periodic) Interrupt Flag
Set periodically. Refer to RTR[1:0] bits in PACTL register.
PAOVF — Pulse Accumulator Overflow Interrupt Flag
Refer to 9 Pulse Accumulator.
PAIF — Pulse Accumulator Input Edge Interrupt Flag
Refer to 9 Pulse Accumulator.
PACTL — Pulse Accumulator Control
Bit 7
6
5
4
3
DDRA7 PAEN PAMOD PEDGE
0
RESET:
0
0
0
0
0
$1026
2
1
Bit 0
0
RTR1 RTR0
0
0
0
DDRA7 — Data Direction for Port A Bit 7
Refer to 5 Parallel Input/Output.
PAEN — Pulse Accumulator Enable
Refer to 9 Pulse Accumulator.
PAMOD — Pulse Accumulator Mode Select
Refer to 9 Pulse Accumulator.
PEDGE — Pulse Accumulator Edge Select
Refer to 9 Pulse Accumulator.
RTR [1:0] — Real-Time Interrupt (RTI) Rate
RTR[1:0]
00
01
10
11
Table 8 Real-Time Interrupt Rates
Divide E By
2¹³
2¹⁴
2¹⁵
2¹⁶
E=
XTAL = 4.0 MHz
8.19 ms
16.38 ms
32.77 ms
65.54 ms
1.0 MHz
XTAL = 8.0 MHz
4.096 ms
8.192 ms
16.384 ms
32.768 ms
2.0 MHz
XTAL = 12.0 MHz
2.731 ms
5.461 ms
10.923 ms
21.845 ms
3.0 MHz
MC68HC11A8
MC68HC11A8TS/D
MOTOROLA
37