5-42

Features

• Two Operating Modes

- Mode 0 - Functionally Compatible with Industry

Types Such as the TR1602A and CDP6402

- Mode 1 - Interfaces Directly with CDP1800-Series

Microprocessors without Additional Components

• Full or Half Duplex Operation

• Parity, Framing and Overrun Error Detection

• Baud Rate

• Fully Programmable with Externally Selectable Word

Length (5-8 Bits), Parity Inhibit, Even/Odd Parity, and

1, 1-1/2, or 2 Stop Bits

• False Start Bit Detection

Description

The CDP1854A and CDP1854AC are silicon-gate CMOS

Universal Asynchronous Receiver/Transmitter (UART) cir-

cuits. They are designed to provide the necessary formatting

and control for interfacing between serial and parallel data.

For example, these UARTs can be used to interface between

a peripheral or terminal with serial I/O ports and the 8-bit

CDP1800-series microprocessor parallel data bus system.

The CDP1854A is capable of full duplex operation, i.e.,

simultaneous conversion of serial input data to parallel out-

put data and parallel input data to serial output data.

The CDP1854A UART can be programmed to operate in one

of two modes by using the mode control input. When the

input is high (MODE = 1), the CDP1854A is directly compati-

ble with the CDP1800-series microprocessor system without

additional interface circuitry. When the mode input is low

(MODE = 0), the device is functionally compatible with indus-

try standard UART’s such as the TR1602A and CDP6402. It

is also pin compatible with these types, except that pin 2 is

used for the mode control input.

The CDP1854A and the CDP1854AC are functionally identi-

cal. The CDP1854A has a recommended operating voltage

range of 4V to 10.5V, and the CDP1854AC has a recom-

mended operating voltage range of 4V to 6.5V.

Ordering Information

PACKAGE

TEMP.

RANGE

5V/200K

BAUD

10V/400K

BAUD

PKG.

NO.

PDIP

CDP1854AE

E40.6

Burn-In

CDP1854ACEX

CDP1854AEX

E40.6

PLCC

CDP1854AQ

N44.65

SBDIP

CDP1854AD

D40.6

Burn-In

CDP1854ACDX

-

D40.6

March 1997

CDP1854A,

CDP1854AC

Programmable Universal Asynchronous

Receiver/Transmitter (UART)

File Number

1193.2

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

http://www.intersil.com or 407-727-9207