Lucent Technologies MN10285K - Manual (Page 114)

Timers
16-Bit Timer Setup Examples
MN102H75K/F75K/85K/F85K LSI User Manual Panasonic Semiconductor Development Company
113
Panasonic
■ To service the interrupts:
Run the interrupt service routine. The routine must determine the interrupt group,
then clear the interrupt request flag.
Timer 5 can input a two-phase encoder signal. Timer 5 does not operate in STOP
mode, when B
OSC
is off. If you use an external clock, it must be synchronized to
B
OSC
.
Table 4-4 shows the count direction for the timing diagram in figure 4-42. In
down counting, when the binary counter reaches 0, it loops to the value in
TM5CA. An interrupt B occurs when the contents of TM5BC match those of
TM5CB.
Table 4-4 Count Direction for 4x Two-Phase Encoder Timing Example
Up Counting Down Counting
TM5IA
↑
1
↓
0
↑
0
↓
1
TM5IB 0
↑
1
↓
1
↑
0
↓
Figure 4-42 4x Two-Phase Encoder Input Timing (Timer 5)
TM5CA
TM5CB
TM5IA
TM5BC
TM5IB
Interrupt
0000 1FFF 1FFE 1FFD 1FFE 1FFF
1FFF
0000 0001 0FFF 1000
1000
1001
B