850
SAM4CP [DATASHEET]
43051E–ATPL–08/14
38.5
Product Dependencies
38.5.1 I/O Lines
The pins used for interfacing the PWM may be multiplexed with PIO lines. The programmer must first program the PIO
controller to assign the desired PWM pins to their peripheral function. If I/O lines of the PWM are not used by the
application, they can be used for other purposes by the PIO controller.
All of the PWM outputs may or may not be enabled. If an application requires only four channels, then only four PIO lines
will be assigned to PWM outputs.
38.5.2 Power Management
The PWM is not continuously clocked. The programmer must first enable the PWM clock in the Power Management
Controller (PMC) before using the PWM. However, if the application does not require PWM operations, the PWM clock
can be stopped when not needed and be restarted later. In this case, the PWM will resume its operations where it left off.
All the PWM registers except PWM_CDTY and PWM_CPRD can be read without the PWM peripheral clock enabled. All
the registers can be written without the peripheral clock enabled.
38.5.3 Interrupt Sources
The PWM interrupt line is connected on one of the internal sources of the Interrupt Controller. Using the PWM interrupt
requires the Interrupt Controller to be programmed first. Note that it is not recommended to use the PWM interrupt line in
edge sensitive mode.
38.6
Functional Description
The PWM macrocell is primarily composed of a clock generator module and 4 channels.
Clocked by the system clock, MCK, the clock generator module provides 13 clocks.
Each channel can independently choose one of the clock generator outputs.
Each channel generates an output waveform with attributes that can be defined independently for each
channel through the user interface registers.
Table 38-2.
I/O Lines
Instance
Signal
I/O Line
Peripheral
PWM
PWM0
PC0
B
PWM
PWM0
PC6
A
PWM
PWM1
PC1
B
PWM
PWM1
PC7
A
PWM
PWM2
PC2
B
PWM
PWM2
PC8
A
PWM
PWM3
PC3
B
PWM
PWM3
PC9
A
Table 38-3.
Peripheral IDs
Instance
ID
PWM
41