LM3S2739 Datasheet, PDF (474/532 Pages) List of Unclassifed Manufacturers – Microcontroller

Pulse Width Modulator (PWM)
Register 34: PWM0 Generator A Control (PWM0GENA), offset 0x060
Register 35: PWM1 Generator A Control (PWM1GENA), offset 0x0A0
Register 36: PWM2 Generator A Control (PWM2GENA), offset 0x0E0
These registers control the generation of the PWMnA signal based on the load and zero output pulses
from the counter, as well as the compare A and compare B pulses from the comparators
(PWM0GENA controls the PWM generator 0 block, and so on). When the counter is running in
Count-Down mode, only four of these events occur; when running in Count-Up/Down mode, all six
occur. These events provide great flexibility in the positioning and duty cycle of the PWM signal that
is produced.
The PWM0GENA register controls generation of the PWM0A signal; PWM1GENA, the PWM1A signal;
and PWM2GENA, the PWM2A signal.
Each field in these registers can take on one of the values defined in Table 18-2 on page 475, which
defines the effect of the event on the output signal.
If a zero or load event coincides with a compare A or compare B event, the zero or load action is
taken and the compare A or compare B action is ignored. If a compare A event coincides with a
compare B event, the compare A action is taken and the compare B action is ignored.
PWM0 Generator A Control (PWM0GENA)
Base 0x4002.8000
Offset 0x060
Type R/W, reset 0x0000.0000
31
30
29
28
27
26
Type RO
Reset
0
15
Type RO
Reset
0
RO
RO
0
0
14
13
reserved
RO
RO
0
0
RO
RO
RO
0
0
0
12
11
10
ActCmpBD
RO
R/W
R/W
0
0
0
25
24
23
22
reserved
RO
RO
RO
RO
0
0
0
0
9
8
ActCmpBU
R/W
R/W
0
0
7
6
ActCmpAD
R/W
R/W
0
0
21
20
RO
RO
0
0
5
4
ActCmpAU
R/W
R/W
0
0
19
18
RO
RO
0
0
3
2
ActLoad
R/W
R/W
0
0
17
16
RO
RO
0
0
1
0
ActZero
R/W
R/W
0
0
Bit/Field
31:12
11:10
9:8
7:6
Name
reserved
ActCmpBD
ActCmpBU
ActCmpAD
Type
RO
R/W
R/W
R/W
Reset
0
0
0
0
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.
The action to be taken when the counter matches comparator B while
counting down.
See Table 18-2 on page 475, which defines the effect of the event on
the output signal.
The action to be taken when the counter matches comparator B while
counting up. Occurs only when the Mode bit in the PWMnCTL register
(see page 465) is set to 1.
See Table 18-2 on page 475, which defines the effect of the event on
the output signal.
The action to be taken when the counter matches comparator A while
counting down.
See Table 18-2 on page 475, which defines the effect of the event on
the output signal.
474
June 04, 2007
Preliminary