© 1999 Fairchild Semiconductor Corporation

DS009535

www.fairchildsemi.com

April 1988

Revised August 1999

74F402

Serial Data Polynomial Generator/Checker

General Description

The 74F402 expandable Serial Data Polynomial generator/

checker is an expandable version of the 74F401. It pro-

vides an advanced tool for the implementation of the most

widely used error detection scheme in serial digital han-

dling systems. A 4-bit control input selects one-of-six gen-

erator polynomials. The list of polynomials includes CRC-

16, CRC-CCITT and Ethernet

®, as well as three other

Individual clear and preset inputs are provided for floppy

disk and other applications. The Error output indicates

whether or not a transmission error has occurred. The

CWG Control input inhibits feedback during check word

transmission. The 74F402 is compatible with FAST

®

devices and with all TTL families.

Features

s Guaranteed 30 MHz data rate

s Six selectable polynomials

s Other polynomials available

s Separate preset and clear controls

s Expandable

s Automatic right justification

s Error output open collector

s Typical applications: Floppy and other disk storage sys-

tems Digital cassette and cartridge systems Data com-

munication systems

Ordering Code:

Logic Symbol

Connection Diagram

FAST

® is a registered trademark of Fairchild Semiconductor Corporation.

Ethernet

® is a registered trademark of Xerox Corporation.

Order Number

Package Number

Package Description

74F402PC

N16E

16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide