sdkuo@argo.acs.oakland.edu (04/11/91)
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 sdkuo@argo.acs.oakland.edu sdkuo@vela.UUCP Oakland University, Rochester, Michigan, USA "Go Green, Go MSU"
deanr@sco.COM (Dean Reece) (04/15/91)
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
heke@stekt.oulu.fi (Heikki Paananen) (04/18/91)
Greetings,
Steven D. Kuo was searching for a 8 digit display driver.
Well, I am not sure if this would give any help, but
one which drives 6 digits is
MM74C917
It is a CMOS chip packed in 28-pin DIL case.
It requires 6 external transistors and 8 resistors (supports
decimal point usage). No capacitors required for the multiplexer
oscillator. Internal registers, 7-segment decoder and register
address decoder.
I think National semiconductor is one of its manufacturers.
Cheers,
HEKE
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Heikki Paananen heke@stekt.oulu.fi
The University of Oulu hpa@stek1.oulu.fi
Department of electrical engineering so-hsp@finou.oulu.fi
Finland
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All the World is a Stage
but Some Stages are Transistorised -Les Sage