
Timing System
Output Compare
M68HC11E Family — Rev. 5
Data Sheet
MOTOROLA
Timing System
155
9.4.9 Timer Interrupt Mask 2 Register
Use this 8-bit register to enable or inhibit timer overflow and real-time interrupts.
The timer prescaler control bits are included in this register.
TOI — Timer Overflow Interrupt Enable Bit
0 = TOF interrupts disabled
1 = Interrupt requested when TOF is set to 1
RTII — Real-Time Interrupt Enable Bit
Refer to
9.5 Real-Time Interrupt (RTI)
.
PAOVI — Pulse Accumulator Overflow Interrupt Enable Bit
Refer to
9.7.3 Pulse Accumulator Status and Interrupt Bits
.
PAII — Pulse Accumulator Input Edge Interrupt Enable Bit
Refer to
9.7.3 Pulse Accumulator Status and Interrupt Bits
.
Bits [3:2] — Unimplemented
Always read 0
PR[1:0] — Timer Prescaler Select Bits
These bits are used to select the prescaler divide-by ratio. In normal modes,
PR[1:0] can be written only once, and the write must be within 64 cycles after
reset. Refer to
Table 9-1
and
Table 9-4
for specific timing values.
NOTE:
Bits in TMSK2 correspond bit for bit with flag bits in TFLG2. Bits in TMSK2 enable
the corresponding interrupt sources.
Address:
$1024
Bit 7
6
5
4
3
2
1
Bit 0
Read:
TOI
RTII
PAOVI
PAII
PR1
PR0
Write:
Reset:
0
0
0
0
0
0
0
0
= Unimplemented
Figure 9-19. Timer Interrupt Mask 2 Register (TMSK2)
Table 9-4. Timer Prescale
PR[1:0]
Prescaler
0 0
1
0 1
4
1 0
8
1 1
16
F
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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.