Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!sco!deanr
From: deanr@sco.COM (Dean Reece)
Newsgroups: sci.electronics
Subject: Re: 7-Segment Display Driver
Message-ID: <11385@scolex.sco.COM>
Date: 15 Apr 91 16:46:24 GMT
References: <5796@vela.acs.oakland.edu>
Sender: news@sco.COM
Lines: 31


sdkuo@argo.acs.oakland.edu writes:

>I looking for a certain logic chip that I know exists.
>It's an 8 digit 7-segment display driver with memory.  You simply
>select which digit to update (with address lines), and give it the
>value.  The chip will remember all 8 digits and display them with
>automatic refresh.  Does anyone know of this chip?  If so, please
>let me know.

>thanks,
>Steven D. Kuo

I'm not sure if this is the chip you are thinking of, but it'll do
everything you asked for.  Its the Intel 8279 Keyboard/Display Interface.

It expects a microprocessor type interface, but has the ability to drive
a 16 digit multiplex display at 4 bits/digit (you add 7447) or an 8 digit
display at 8 bits/digit (1 bit per segment, you provide LED drivers).
As it scans the display, it also scans a keyboard/sensor array.

From the microprocessor side, you can configure the chip for several modes
of operation.  The display can be used as you say above (addressed as
specific digits) or it can be shifted into from the right or left, or
scrolled across right or left.  The keyboard info can be buffered up to
8 bytes deep by 8 bits wide (6 bits to specify 1 of 64 keys, 2 bits for
shift and cntrl status). 

Its pretty nifty, even if its not the latest-n-greatest silicon.

-deanr@sco.com