LM3S1651 Datasheet, PDF (45/1033 Pages) Texas Instruments – ARM and Thumb are registered trademarks and Cortex is a trademark

Stellaris^® LM3S1651 Microcontroller
1.3.3.1
■ Two Synchronous Serial Interface modules (SSI)
■ Integrated Interchip Sound (I²S) module
The following sections provide more detail on each of these communications functions.
UART (see page 613)
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 LM3S1651 microcontroller includes three fully programmable 16C550-type UARTs. Although
the functionality is similar to a 16C550 UART, this UART design is not register compatible. The
UART can generate individually masked interrupts from the Rx, Tx, modem flow control, modem
status, and error conditions. The module generates a single combined interrupt when any of the
interrupts are asserted and are unmasked.
The three UARTs have the following features:
■ Programmable baud-rate generator allowing speeds up to 5 Mbps for regular speed (divide by
16) and 10 Mbps for high speed (divide by 8)
■ Separate 16x8 transmit (TX) and receive (RX) FIFOs to reduce CPU interrupt service loading
■ Programmable FIFO length, including 1-byte deep operation providing conventional
double-buffered interface
■ FIFO trigger levels of 1/8, 1/4, 1/2, 3/4, and 7/8
■ Standard asynchronous communication bits for start, stop, and parity
■ Line-break generation and detection
■ Fully programmable serial interface characteristics
– 5, 6, 7, or 8 data bits
– Even, odd, stick, or no-parity bit generation/detection
– 1 or 2 stop bit generation
■ IrDA serial-IR (SIR) encoder/decoder providing
– Programmable use of IrDA Serial Infrared (SIR) or UART input/output
– Support of IrDA SIR encoder/decoder functions for data rates up to 115.2 Kbps half-duplex
– Support of normal 3/16 and low-power (1.41-2.23 μs) bit durations
– Programmable internal clock generator enabling division of reference clock by 1 to 256 for
low-power mode bit duration
■ Support for communication with ISO 7816 smart cards
■ Full modem handshake support (on UART1)
January 21, 2012
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