23.2
Signal Description
The following table lists the external signals of the PWM module and describes the function of each.
The PWM controller signals are alternate functions for some GPIO signals and default to be GPIO
signals at reset. The column in the table below titled "Pin Mux/Pin Assignment" lists the possible
GPIO pin placements for these PWM signals. The
AFSEL
bit in the
GPIO Alternate Function Select
(GPIOAFSEL)
register (page 770) should be set to choose the PWM function. The number in
parentheses is the encoding that must be programmed into the
PMCn
field in the
GPIO Port Control
(GPIOPCTL)
register (page 787) to assign the PWM signal to the specified GPIO port pin. For more
information on configuring GPIOs, see “General-Purpose Input/Outputs (GPIOs)” on page 742.
Table 23-1. PWM Signals (128TQFP)
Description
Buffer Type
Pin Type
Pin Mux / Pin
Assignment
Pin Number
Pin Name
Motion Control Module 0 PWM Fault 0.
TTL
I
PF4 (6)
46
M0FAULT0
Motion Control Module 0 PWM Fault 1.
TTL
I
PK6 (6)
61
M0FAULT1
Motion Control Module 0 PWM Fault 2.
TTL
I
PK7 (6)
60
M0FAULT2
Motion Control Module 0 PWM Fault 3.
TTL
I
PL0 (6)
81
M0FAULT3
Motion Control Module 0 PWM 0. This signal is
controlled by Module 0 PWM Generator 0.
TTL
O
PF0 (6)
42
M0PWM0
Motion Control Module 0 PWM 1. This signal is
controlled by Module 0 PWM Generator 0.
TTL
O
PF1 (6)
43
M0PWM1
Motion Control Module 0 PWM 2. This signal is
controlled by Module 0 PWM Generator 1.
TTL
O
PF2 (6)
44
M0PWM2
Motion Control Module 0 PWM 3. This signal is
controlled by Module 0 PWM Generator 1.
TTL
O
PF3 (6)
45
M0PWM3
Motion Control Module 0 PWM 4. This signal is
controlled by Module 0 PWM Generator 2.
TTL
O
PG0 (6)
49
M0PWM4
Motion Control Module 0 PWM 5. This signal is
controlled by Module 0 PWM Generator 2.
TTL
O
PG1 (6)
50
M0PWM5
Motion Control Module 0 PWM 6. This signal is
controlled by Module 0 PWM Generator 3.
TTL
O
PK4 (6)
63
M0PWM6
Motion Control Module 0 PWM 7. This signal is
controlled by Module 0 PWM Generator 3.
TTL
O
PK5 (6)
62
M0PWM7
23.3
Functional Description
23.3.1
Clock Configuration
The PWM has two clock source options:
■ The System Clock
■ A predivided System Clock
The clock source is selected by programming the
USEPWM
bit in the
PWM Clock Configuration
(PWMCC)
register. The
PWMDIV
bitfield specifies the divisor of the System Clock that is used to
create the PWM Clock.
23.3.2
PWM Timer
The timer in each PWM generator runs in one of two modes: Count-Down mode or Count-Up/Down
mode. In Count-Down mode, the timer counts from the load value to zero, goes back to the load
June 18, 2014
1672
Texas Instruments-Production Data
Pulse Width Modulator (PWM)