MC68HC908RK2 Datasheet, PDF (199/232 Pages) Motorola, Inc – Microcontroller Unit

Timer Interface Module (TIM)
Functional Description
Addr. Register Name
Bit 7
6
5
4
3
2
Read:
Timer Channel 1 Register
Bit 15
14
$0029
High (TCH1H)) Write:
See page 216.
Reset:
13
12
11
10
Indeterminate after reset
Read:
Timer Channel 1 Register
Bit 7
6
$002A
Low (TCH1L)) Write:
See page 216.
Reset:
5
4
3
2
Indeterminate after reset
= Unimplemented
Figure 15-2. TIM I/O Register Summary (Continued)
1
Bit 0
9
Bit 8
1
Bit 0
15.5.1 TIM Counter Prescaler
The TIM clock source can be one of the seven prescaler outputs or the
TIM clock pin, TCLK. The prescaler generates seven clock rates from
the internal bus clock. The prescaler select bits, PS[2:0], in the TIM
status and control register select the TIM clock source.
15.5.2 Input Capture
With the input capture function, the TIM can capture the time at which an
external event occurs. When an active edge occurs on the pin of an input
capture channel, the TIM latches the contents of the TIM counter into the
TIM channel registers, TCHxH and TCHxL. The polarity of the active
edge is programmable. Input captures can generate TIM CPU interrupt
requests.
15.5.3 Output Compare
With the output compare function, the TIM can generate a periodic pulse
with a programmable polarity, duration, and frequency. When the
counter reaches the value in the registers of an output compare channel,
the TIM can set, clear, or toggle the channel pin. Output compares can
generate TIM CPU interrupt requests.
MC68HC908RK2 — Rev. 4.0
MOTOROLA
Timer Interface Module (TIM)
Advance Information
199