LM3S6422 Luminary Micro, Inc, LM3S6422 Datasheet - Page 32

• Manufacturer Part Number: LM3S6422
• Description: Lm3s6422 Arm Microcontroller
• Manufacturer: Luminary Micro, Inc

Architectural Overview
1.4.4.1
1.4.4.2
1.4.4.3
1.4.5
1.4.5.1
32
UART (see page 275)
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 LM3S6422 controller includes one fully programmable 16C550-type UARTthat supports data
transfer speeds up to 1.5625 Mbps. (Although similar in functionality to a 16C550 UART, it is not
register-compatible.) In addition, each UART is capable of supporting IrDA.
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 (see page 316)
Synchronous Serial Interface (SSI) is a four-wire bi-directional communications interface.
The LM3S6422 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.
Ethernet Controller (see page 353)
Ethernet is a frame-based computer networking technology for local area networks (LANs). Ethernet
has been standardized as IEEE 802.3. It defines a number of wiring and signaling standards for the
physical layer, two means of network access at the Media Access Control (MAC)/Data Link Layer,
and a common addressing format.
The Stellaris® Ethernet Controller consists of a fully integrated media access controller (MAC) and
network physical (PHY) interface device. The Ethernet Controller conforms to IEEE 802.3
specifications and fully supports 10BASE-T and 100BASE-TX standards. In addition, the Ethernet
Controller supports automatic MDI/MDI-X cross-over correction.
System Peripherals
Programmable GPIOs (see page 141)
General-purpose input/output (GPIO) pins offer flexibility for a variety of connections.
The Stellaris
an individual GPIO port. The GPIO module is FiRM-compliant (compliant to the ARM Foundation
IP for Real-Time Microcontrollers specification) and supports 12-34 programmable input/output pins.
The number of GPIOs available depends on the peripherals being used (see “Signal Tables” on page
411 for the signals available to each GPIO pin).
®
GPIO module is comprised of seven physical GPIO blocks, each corresponding to
Preliminary
July 25, 2008