Timer Interface Module B (TIMB)
Technical Data
MC68HC08AZ32A — Rev 1.0
262
Timer Interface Module B (TIMB)
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MOTOROLA
17.4 Functional Description
Figure 17-1
shows the TIMB structure. The central component of the
TIMB is the 16-bit TIMB counter that can operate as a free-running
counter or a modulo up-counter. The TIMB counter provides the timing
reference for the input capture and output compare functions. The TIMB
counter modulo registers, TBMODH–TBMODL, control the modulo
value of the TIMB counter. Software can read the TIMB counter value at
any time without affecting the counting sequence.
The two TIMB channels are programmable independently as input
capture or output compare channels.
17.4.1 TIMB Counter Prescaler
The TIMB clock source can be one of the seven prescaler outputs or the
TIMB clock pin, PTD4/ATD12/TBCLK. The prescaler generates seven
clock rates from the internal bus clock. The prescaler select bits, PS[2:0],
in the TIMB status and control register select the TIMB clock source.
$0047
TIMB Ch. 0 Register Low (TBCH0L)
R:
W:
Bit 7
6
5
4
3
2
1
Bit 0
$0048
TIMB Ch. 1 Status/Control Register
(TBSC1)
R:
CH1F
0
CH1IE
0
R
MS1A
ELS1B
ELS1A
TOV1
CH1MAX
W:
$0049
TIMB Ch. 1 Register High (TBCH1H)
R:
W:
R:
W:
Bit 15
14
13
12
11
10
9
Bit 8
$004A
TIMB Ch. 1 Register Low (TBCH1L)
Bit 7
6
5
4
3
2
1
Bit 0
R
= Reserved
Figure 17-2. TIMB I/O Register Summary
Addr.
Register Name
Bit 7
6
5
4
3
2
1
Bit 0
F
Freescale Semiconductor, Inc.
n
.