LM3S328 Datasheet, PDF (26/371 Pages) List of Unclassifed Manufacturers – Microcontroller

Architectural Overview
1.4.4
1.4.4.1
1.4.4.2
1.4.4.3
The Stellaris ADC module features 10-bit conversion resolution and supports eight input channels,
plus an internal temperature sensor. Four buffered sample sequences allow rapid sampling of up
to eight analog input sources without controller intervention. Each sample sequence provides
flexible programming with fully configurable input source, trigger events, interrupt generation, and
sequence priority.
Serial Communications Peripherals
The LM3S328 controller supports both asynchronous and synchronous serial communications
with two fully programmable 16C550-type UARTs, SSI and I²C serial communications.
UART (Section 12 on page 235)
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 LM3S328 controller includes two fully programmable 16C550-type UARTs that support data
transfer speeds up to 460.8 Kbps. (Although similar in functionality to a 16C550 UART, it is not
register compatible.)
Separate 16x8 transmit (TX) and 16x12 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 (Section 13 on page 271)
Synchronous Serial Interface (SSI) is a four-wire bi-directional communications interface.
The Stellaris SSI module 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.
I²C (Section 14 on page 306)
The Inter-Integrated Circuit (I²C) bus provides bi-directional data transfer through a two-wire
design (a serial data line SDA and a serial clock line SCL).
The I²C bus interfaces to external I²C devices such as serial memory (RAMs and ROMs),
networking devices, LCDs, tone generators, and so on. The I²C bus may also be used for system
testing and diagnostic purposes in product development and manufacture.
The Stellaris I²C module provides the ability to communicate to other IC devices over an I²C bus.
The I²C bus supports devices that can both transmit and receive (write and read) data.
Devices on the I²C bus can be designated as either a master or a slave. The I²C module supports
both sending and receiving data as either a master or a slave, and also supports the simultaneous
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April 27, 2007
Preliminary