Texas Instruments 4Q 2006 manual UARTs Universal Asynchronous Receiver/Transmitters

16UARTs (Universal Asynchronous Receiver/Transmitters)

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Design Considerations

The UART is a key component of an asynchronous serial communications system. For example, all internal modems have their own UARTs. In this application, parallel data within the computer is converted by the UART to serial data before being transferred to the modem. In addition to PC/peripheral communication, UARTs can be used for chip-to-chip communications.

As data transfer speeds have increased to support applications such as telecommunica- tion base stations, cell phones, PCs, fax servers and rack modems, the transmission rate of the UART has become critical to

preventing system bottlenecks. When a fast external modem is used, designers should be sure the computer’s UART can handle the modem’s maximum transmission rate. For example, the TL16C550D UART contains a

16-byte buffer, enabling it to support higher sustained transmission rates than the older 8250 UART. To reduce software buffering and data overruns, TI has added its patented hardware autoflow control to all new designs and most existing UARTs. Most UARTs allow the divisor to be programmed from 1 to 65,535 and sometimes with an added predivisor factor of 1, 4, 16 or 64.

To accommodate the requirements of diverse applications, TI offers a wide portfolio of parallel-to-serial and serial-to-parallel UARTs in highly integrated, space-saving configura- tions that allow designers to increase system performance while decreasing space requirements.

As one of the world’s leading high-volume semiconductor manufacturers, TI offers designers and OEMs the satisfaction of knowing they are backed by a supplier with the resources to meet their needs. These include a dedicated marketing and technical support team to assist with any issues.

Key Features

•Single-, dual- and quad-channel devices

•16- and 64-byte FIFOs available

•5-, 3.3-, 2.5- and 1.8-V supply

•Clock rates up to 24/20/16-MHz for 1.5/1.25/1.0-Mbps data transfer rates

•Hardware and software autoflow control

•Programmable sleep mode and low-power mode

•Industrial temperature characterization

UART Family of Products

TL16C754B

	4
			TL16C554A
Channels			TL16C2552
				TL16C2752
			TL16C2550
	2	TL16C452
				TL16C752B
			TL16C552A
		TL16C451	TL16C550D
	1
		TL16C450	TL16C550C
				TL16C750

TL16PC564B

TL16PIR552A

TIR1000

No FIFO	16-Byte	64-Byte	Special
	FIFO Memory Size		Functions

Interface Selection Guide Texas Instruments 4Q 2006