W83C42
KEYBOARD CONTROLLER
GENERAL DESCRIPTION
The W83C42 keyboard controller is programmed to support the IBM
®
compatible personal computer
keyboard serial interface. The keyboard controller receives serial data from the keyboard, checks the
parity of the data, translates the scan code, and presents the data to the system as a byte of data in
its output buffer. The controller will interrupt the system when data is placed in its output buffer. The
byte of data will be sent to the keyboard serially with an odd parity bit automatically inserted. The
keyboard is required to acknowledge all data transmissions. No transmission should be sent to the
keyboard until acknowledge is received for the previous byte sent.
Winbond Electronics Corporation has developed a fast keyboard controller and BIOS to improve the
performance of IBM PC/AT
®
386
™
DX/SX and 486
™
DX/SX machines and their compatibles. Hardwire
methodology is used in this keyboard controller instead of software implementation, as in the
traditional 8042 keyboard BIOS. This enables the keyboard controller to respond instantly to all
commands sent from the keyboard to the CPU BIOS.
The keyboard controller enables popular programs such as AutoCAD
®
, Microsoft
®
Windows
™
3.1,
NOVELL
®
, and other programs to run much faster.
FEATURES
•
•
•
•
•
•
•
Supports IBM PC/AT 386DX/SX and 486 DX/SX system designs
Runs much faster than traditional keyboard controllers
Host interface compatible with traditional keyboard controller
6MHz~12MHz operating frequency
Communicates with keyboard directly
High-reliability CMOS technology
Available packages: 40-pin DIP, 44-pin PLCC
IBM and PC/AT are registered trademarks of International Business Machines Corporation. 386 and 486 are trademarks of Intel
Corporation. AutoCAD is a registered trademark of Autodesk, Inc. Microsoft is a registered trademark and Windows is a trademark of
Microsoft Corporation. NOVELL is a registered trademark of Novell, Inc.
-1-
Publication Release Date: July 1994
Revision A3
WINBOND [ WINBOND ]
