SC16C2550B datasheet(9/43 Pages) PHILIPS

9 / 43 page

SC16C2550B_4

Product data sheet

Rev. 04 — 15 February 2007

9 of 43

NXP Semiconductors

SC16C2550B

5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs

Functional description

The SC16C2550B provides serial asynchronous receive data synchronization,

parallel-to-serial and serial-to-parallel data conversions for both the transmitter and

receiver sections. These functions are necessary for converting the serial data stream into

parallel data that is required with digital data systems. Synchronization for the serial data

stream is accomplished by adding start and stop bits to the transmit data to form a data

character (character orientated protocol). Data integrity is insured by attaching a parity bit

to the data character. The parity bit is checked by the receiver for any transmission bit

errors. The electronic circuitry to provide all these functions is fairly complex, especially

when manufactured on a single integrated silicon chip. The SC16C2550B represents such

an integration with greatly enhanced features. The SC16C2550B is fabricated with an

advanced CMOS process.

The SC16C2550B is an upward solution that provides a dual UART capability with

16 bytes of transmit and receive FIFO memory, instead of none in the 16C2450. The

SC16C2550B is designed to work with high speed modems and shared network

environments that require fast data processing time. Increased performance is realized in

the SC16C2550B by the transmit and receive FIFOs. This allows the external processor to

handle more networking tasks within a given time. For example, the ST16C2450 without a

receive FIFO, will require unloading of the RHR in 93 microseconds (this example uses a

character length of 11 bits, including start/stop bits at 115.2 kbit/s). This means the

external CPU will have to service the receive FIFO less than every 100 microseconds.

However, with the 16-byte FIFO in the SC16C2550B, the data buffer will not require

unloading/loading for 1.53 ms. This increases the service interval, giving the external CPU

additional time for other applications and reducing the overall UART interrupt servicing

time. In addition, the four selectable receive FIFO trigger interrupt levels are uniquely

provided for maximum data throughput performance especially when operating in a

multi-channel environment. The FIFO memory greatly reduces the bandwidth requirement

of the external controlling CPU, increases performance and reduces power consumption.

The SC16C2550B is capable of operation up to 5 Mbit/s with a 80 MHz clock. With a

crystal or external clock input of 7.3728 MHz, the user can select data rates up to

460.8 kbit/s.

The rich feature set of the SC16C2550B is available through internal registers. Selectable

receive FIFO trigger levels, selectable TX and RX baud rates and modem interface

controls are all standard features. Following a power-on reset or an external reset, the

SC16C2550B is software compatible with the previous generation, ST16C2450.

6.1 UART A-B functions

The UART provides the user with the capability to bidirectionally transfer information

between an external CPU, the SC16C2550B package and an external serial device. A

logic 0 on chip select pins CSA and/or CSB allows the user to conﬁgure, send data,

and/or receive data via UART channels A through B. Individual channel select functions

are shown in Table 4.

SC16C2550B датащи(PDF) 9 Page - NXP Semiconductors

SC16C2550B датащи(HTML) 9 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43

датащи скачать

ссылки URL