LM3S1651 Datasheet, PDF (858/1033 Pages) Texas Instruments – ARM and Thumb are registered trademarks and Cortex is a trademark

Pulse Width Modulator (PWM)
Register 33: PWM0 Compare B (PWM0CMPB), offset 0x05C
Register 34: PWM1 Compare B (PWM1CMPB), offset 0x09C
Register 35: PWM2 Compare B (PWM2CMPB), offset 0x0DC
These registers contain a value to be compared against the counter (PWM0CMPB controls the
PWM generator 0 block, and so on). When this value matches the counter, a pulse is output which
can be configured to drive the generation of the pwmA and pwmB signals (via the PWMnGENA
and PWMnGENB registers) or drive an interrupt or ADC trigger (via the PWMnINTEN register). If
the value of this register is greater than the PWMnLOAD register, no pulse is ever output.
If the comparator B update mode is locally synchronized (based on the CMPBUPD bit in the PWMnCTL
register), the 16-bit COMPB value is used the next time the counter reaches zero. If the update mode
is globally synchronized, it is used the next time the counter reaches zero after a synchronous
update has been requested through the PWM Master Control (PWMCTL) register (see page 822).
If this register is rewritten before the actual update occurs, the previous value is never used and is
lost.
PWM0 Compare B (PWM0CMPB)
PWM0 base: 0x4002.8000
Offset 0x05C
Type R/W, reset 0x0000.0000
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
reserved
Type RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
COMPB
Type R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bit/Field
31:16
15:0
Name
reserved
COMPB
Type
RO
R/W
Reset
0x0000
0x0000
Description
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
Comparator B Value
The value to be compared against the counter.
858
January 21, 2012
Texas Instruments-Production Data