Rajnish wrote:
>Would appreciate if you can send me your asm code for the ICM7218.

Rajnish,

I'm afraid that I can't be of much help.  I wrote the code a while ago for a
 client
and didn't keep a copy per his request.  I wrote it in FORTH for the 8051
 family, at
any rate.

The `7218 is pretty straight-forward, though.  It has four data lines for the
 digit
values (0-9 plus A-F in one mode and 0-9 plus "-HELP" in another), plus one for
 the
decimal point if you need it.  It has three address lines to select digits 0
 thru 7,
and a low-active write line.

Just output your data and address logic and then toggle the _WRITE_ pin low.  As
 I
recall, there was a small problem with timing.  Mostly because I didn't
 understand
their verbiage in the specs.  As long as you adhered to a low _WRITE_ pulse of
 400nS
or more -- and keep the data/address info stable for 125nS *after* the _WRITE_
 strobe
goes *HIGH*, you'll have no problems.  Of course if you have a slower clock
 speed
then this won't even be a concern.

The `7218 is such and expensive chip and is limited to only 8 LED's, I want to
 design
a PIC-based controller to do more LED's at a cheaper price.  I am a consultant
working away from home right now (thus the delay in responding), but when I get
 back
home (~late Feb.) I want to make a `54-based 7-segment LED controller which does
 at
least 12 digits for a clock project that I have.  I could keep you posted on my
progress if you like.

Sorry I can't be of more help.  Good luck on your project.

Michael

When the way of the Tao is forgotten, kindness and ethics must be taught.
Men must learn to pretend to be wise and good.  --  Lao Tzu