LM3S601 Datasheet, PDF (29/446 Pages) List of Unclassifed Manufacturers – Microcontroller

LM3S601 Microcontroller
1.4.4
1.4.4.1
1.4.4.2
1.4.4.3
Serial Communications Peripherals
The LM3S601 controller supports both asynchronous and synchronous serial communications with:
■ Two fully programmable 16C550-type UARTs
■ One SSI module
■ One I²C module
UART (see page 227)
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 LM3S601 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 (see page 265)
Synchronous Serial Interface (SSI) is a four-wire bi-directional communications interface.
The LM3S601 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.
I²C (see page 302)
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 LM3S601 controller includes one I²C module that 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.
October 01, 2007
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Preliminary