Datasheet

■ One Quadrature Encoder Input (QEI)
The following provides more detail on these motion control functions.
1.3.10.1 PWM (see page 1793)
The TM4C129ENCPDT microcontroller contains one PWM module, with four PWM generator blocks
and a control block, for a total of 8 PWM outputs. Pulse width modulation (PWM) is a powerful
technique for digitally encoding analog signal levels. High-resolution counters are used to generate
a square wave, and the duty cycle of the square wave is modulated to encode an analog signal.
Typical applications include switching power supplies and motor control. The TM4C129ENCPDT
PWM module consists of four PWM generator block and a control block. Each PWM generator block
contains one timer (16-bit down or up/down counter), two comparators, a PWM signal generator, a
dead-band generator, and an interrupt/ADC-trigger selector. Each PWM generator block produces
two PWM signals that can either be independent signals or a single pair of complementary signals
with dead-band delays inserted.
Each PWM generator has the following features:
■ Four fault-condition handling inputs to quickly provide low-latency shutdown and prevent damage
to the motor being controlled
■ One 16-bit counter
– Runs in Down or Up/Down mode
– Output frequency controlled by a 16-bit load value
– Load value updates can be synchronized
– Produces output signals at zero and load value
■ Two PWM comparators
– Comparator value updates can be synchronized
– Produces output signals on match
■ PWM signal generator
– Output PWM signal is constructed based on actions taken as a result of the counter and
PWM comparator output signals
– Produces two independent PWM signals
■ Dead-band generator
– Produces two PWM signals with programmable dead-band delays suitable for driving a half-H
bridge
– Can be bypassed, leaving input PWM signals unmodified
■ Can initiate an ADC sample sequence
June 18, 201480
Texas Instruments-Production Data
Architectural Overview