LM3S5956-IQR80-C1 Datasheet, PDF (64/1144 Pages) Texas Instruments – Stellaris® LM3S5956 Microcontroller

Architectural Overview
NRND: Not recommended for new designs.
1.3.5
1.3.5.1
■ Bit masking in both read and write operations through address lines
■ Can be used to initiate an ADC sample sequence
■ Pins configured as digital inputs are Schmitt-triggered
■ Programmable control for GPIO pad configuration
– Weak pull-up or pull-down resistors
– 2-mA, 4-mA, and 8-mA pad drive for digital communication; up to four pads can sink 18-mA
for high-current applications
– Slew rate control for the 8-mA drive
– Open drain enables
– Digital input enables
Advanced Motion Control
The LM3S5956 microcontroller provides motion control functions integrated into the device, including:
■ Six advanced PWM outputs for motion and energy applications
■ Four fault inputs to promote low-latency shutdown
■ One Quadrature Encoder Input (QEI)
The following provides more detail on these motion control functions.
PWM (see page 947)
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 LM3S5956 PWM module consists of three PWM generator blocks 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
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October 06, 2012
Texas Instruments-Production Data