
Technical Data
MC68HC11E Family
—
Rev. 4
202
Timing System
MOTOROLA
Timing System
9.6.3 Pulse Accumulator Control Register
Bits RTR[1:0] of this register select the rate for the RTI system. The
remaining bits control the pulse accumulator and IC4/OC5 functions.
DDRA7
—
Data Direction for Port A Bit 7
Refer to
Section 6. Parallel Input/Output (I/O) Ports
.
PAEN
—
Pulse Accumulator System Enable Bit
Refer to
9.8 Pulse Accumulator
.
PAMOD
—
Pulse Accumulator Mode Bit
Refer to
9.8 Pulse Accumulator
.
PEDGE
—
Pulse Accumulator Edge Control Bit
Refer to
9.8 Pulse Accumulator
.
DDRA3
—
Data Direction for Port A Bit 3
Refer to
Section 6. Parallel Input/Output (I/O) Ports
.
I4/O5
—
Input Capture 4/Output Compare Bit
Refer to
9.8 Pulse Accumulator
.
RTR[1:0]
—
RTI Interrupt Rate Select Bits
These two bits determine the rate at which the RTI system requests
interrupts. The RTI system is driven by an E divided by 2
13
rate clock
that is compensated so it is independent of the timer prescaler. These
two control bits select an additional division factor. Refer to
Table 9-5
.
Address:
$1026
Bit 7
6
5
4
3
2
1
Bit 0
Read:
DDRA7
PAEN
PAMOD
PEDGE
DDRA3
I4/O5
RTR1
RTR0
Write:
Reset:
0
0
0
0
0
0
0
0
Figure 9-23. Pulse Accumulator Control Register (PACTL)