LM3S317 Luminary Micro, Inc, LM3S317 Datasheet - Page 340

• Manufacturer Part Number: LM3S317
• Description: Lm3s317 Arm Microcontroller
• Manufacturer: Luminary Micro, Inc

Pulse Width Modulator (PWM)
340
Reset
Reset
Type
Type
Bit/Field
31:12
11:10
PWMn Generator B Control (PWMnGENB)
9:8
7:6
5:4
3:2
1:0
RO
RO
31
15
0
0
Register 37: PWM0 Generator B Control (PWM0GENB), offset 0x064
Register 38: PWM1 Generator B Control (PWM1GENB), offset 0x0A4
Register 39: PWM2 Generator B Control (PWM2GENB), offset 0x0E4
These registers control the generation of the PWMNB 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
(PWM0GENB controls the PWM generator 0 block, and so on). When the counter is running in
Down mode, only four of these events occur; when running in 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 PWM0GENB register controls generation of the PWM0B signal; PWM1GENB, the PWM1B
signal; and PWM2GENB, the PWM2B signal.
Each field in these registers can take on one of the values defined in Table 15-2 on page 339,
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 B action is taken and the compare A action is ignored.
RO
RO
30
14
0
0
reserved
ActCmpBD
ActCmpBU
ActCmpAD
ActCmpAU
reserved
ActLoad
ActZero
Name
RO
RO
29
13
0
0
RO
RO
28
12
0
0
Type
R/W
R/W
R/W
R/W
R/W
R/W
R/W
RO
RO
27
11
ActCmpBD
0
0
R/W
RO
26
10
0
0
Reset
R/W
RO
25
ActCmpBU
0
9
0
0
0
0
0
0
0
0
Preliminary
R/W
RO
24
0
8
0
reserved
Description
Reserved bits return an indeterminate value, and should
never be changed.
The action to be taken when the counter matches
comparator B while counting down.
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 328) is set
to 1.
The action to be taken when the counter matches
comparator A while counting down.
The action to be taken when the counter matches
comparator A while counting up. Occurs only when the
Mode bit in the PWMnCTL register is set to 1.
The action to be taken when the counter matches the load
value.
The action to be taken when the counter is 0.
R/W
RO
23
ActCmpAD
0
7
0
R/W
RO
22
0
6
0
R/W
RO
21
ActCmpAU
0
5
0
R/W
RO
20
0
4
0
R/W
RO
19
0
3
0
ActLoad
R/W
RO
18
0
2
0
February 6, 2007
R/W
RO
17
0
1
0
ActZero
R/W
RO
16
0
0
0