© 1999 Fairchild Semiconductor Corporation DS009535 www.fairchildsemi.com
April 1988
Revised August 1999
7
4F402 S
e
ria
l
Data Polyno
m
i
al Generat
or/
C
hecker
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
standard polynomials (56
th
order, 48
th
order, 32
nd
order).
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
a73 Guaranteed 30 MHz data rate
a73 Six selectable polynomials
a73 Other polynomials available
a73 Separate preset and clear controls
a73 Expandable
a73 Automatic right justification
a73 Error output open collector
a73 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