MC908JL8CDWE Datasheet, PDF (108/212 Pages) Freescale Semiconductor, Inc – Microcontrollers

Timer Interface Module (TIM)
Addr.
$0034
$0035
$0036
$0037
$0038
$0039
$003A
Register Name
TIM2 Counter Modulo Read:
Register Low Write:
(T2MODL) Reset:
TIM2 Channel 0 Status Read:
and Control Register Write:
(T2SC0) Reset:
TIM2 Channel 0 Read:
Register High Write:
(T2CH0H) Reset:
TIM2 Channel 0 Read:
Register Low Write:
(T2CH0L) Reset:
TIM2 Channel 1 Status Read:
and Control Register Write:
(T2SC1) Reset:
TIM2 Channel 1 Read:
Register High Write:
(T2CH1H) Reset:
TIM2 Channel 1 Read:
Register Low Write:
(T2CH1L) Reset:
Bit 7
Bit 7
1
CH0F
0
0
Bit 15
Bit 7
CH1F
0
0
Bit 15
Bit 7
6
6
1
CH0IE
0
14
5
5
1
MS0B
0
13
6
5
CH1IE
0
0
0
14
13
6
5
= Unimplemented
4
3
2
4
3
2
1
1
1
MS0A ELS0B ELS0A
0
0
0
12
11
10
Indeterminate after reset
4
3
2
Indeterminate after reset
MS1A ELS1B ELS1A
0
0
0
12
11
10
Indeterminate after reset
4
3
2
Indeterminate after reset
Figure 8-2. TIM I/O Register Summary (Sheet 2 of 2)
1
1
1
TOV0
0
9
Bit 0
Bit 0
1
CH0MAX
0
Bit 8
1
Bit 0
TOV1
0
9
CH1MAX
0
Bit 8
1
Bit 0
8.4.1 TIM Counter Prescaler
The TIM1 clock source can be one of the seven prescaler outputs; TIM2 clock source can be one of the
seven prescaler outputs or the TIM2 clock pin, T2CLK. 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.
8.4.2 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:TCHxL. The polarity of the active edge is programmable. Input
captures can generate TIM CPU interrupt requests.
8.4.3 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.
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
108
Freescale Semiconductor