LM3S101 Datasheet, PDF (33/445 Pages) List of Unclassifed Manufacturers – Microcontroller

Stellaris^® LM3S101 Microcontroller
1.4.4.1
1.4.4.2
1.4.5
1.4.5.1
1.4.5.2
UART (see page 301)
A Universal Asynchronous Receiver/Transmitter (UART) is an integrated circuit used for RS-232C
serial communications, containing a transmitter (parallel-to-serial converter) and a receiver
(serial-to-parallel converter), each clocked separately.
The LM3S101 controller includes one fully programmable 16C550-type UARTthat supports data
transfer speeds up to 1.25 Mbps. (Although similar in functionality to a 16C550 UART, it is not
register-compatible.)
Separate 16x8 transmit (TX) and receive (RX) FIFOs reduce CPU interrupt service loading. The
UART can generate individually masked interrupts from the RX, TX, modem status, and error
conditions. The module provides a single combined interrupt when any of the interrupts are asserted
and are unmasked.
SSI (see page 341)
Synchronous Serial Interface (SSI) is a four-wire bi-directional full and low-speed communications
interface.
The LM3S101 controller includes one SSI module that provides the functionality for synchronous
serial communications with peripheral devices, and can be configured to use the Freescale SPI,
MICROWIRE, or TI synchronous serial interface frame formats. The size of the data frame is also
configurable, and can be set between 4 and 16 bits, inclusive.
The SSI module performs serial-to-parallel conversion on data received from a peripheral device,
and parallel-to-serial conversion on data transmitted to a peripheral device. The TX and RX paths
are buffered with internal FIFOs, allowing up to eight 16-bit values to be stored independently.
The SSI module can be configured as either a master or slave device. As a slave device, the SSI
module can also be configured to disable its output, which allows a master device to be coupled
with multiple slave devices.
The SSI module also includes a programmable bit rate clock divider and prescaler to generate the
output serial clock derived from the SSI module's input clock. Bit rates are generated based on the
input clock and the maximum bit rate is determined by the connected peripheral.
System Peripherals
Programmable GPIOs (see page 199)
General-purpose input/output (GPIO) pins offer flexibility for a variety of connections.
The Stellaris GPIO module is comprised of three physical GPIO blocks, each corresponding to an
individual GPIO port. The GPIO module is FiRM-compliant (compliant to the ARM Foundation IP
for Real-Time Microcontrollers specification) and supports 2-18 programmable input/output pins.
The number of GPIOs available depends on the peripherals being used (see “Signal
Tables” on page 393 for the signals available to each GPIO pin).
The GPIO module features programmable interrupt generation as either edge-triggered or
level-sensitive on all pins, programmable control for GPIO pad configuration, and bit masking in
both read and write operations through address lines. Pins configured as digital inputs are
Schmitt-triggered.
Two Programmable Timers (see page 241)
Programmable timers can be used to count or time external events that drive the Timer input pins.
July 14, 2014
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