🚀 go-pugleaf

In article <349D346C.31FE743@stud.uni-erlangen.de>, "D. Meid" <dorian.meid@stud.uni-erlangen.de> writes:
>Can anyone please help me?
>
>I urgently need a IC to perform PWM.
>It should store at least one 16 bit word, compare
>it to a internal counter and trigger a pin when a
>match occurs.
>
>If anyone knows of such a chip or a similar one
>please mail me!
>
>thanks
>dorian
>

I just got this idea  so it might not work at all.
couldn't you use a presetable up/down counter?
here's how:
use preset as input, and clock the counter.
every time the count "hits" 1111111111111111 or 000000000000, you reset the 
counter to the preset and change the counting direction. the direction will 
then be your PWM output.

example:
16 bit counter
preset=12345

counter is presets to 12345 counting up

counter counts from 12345 up to 65536 (53191 clockcycles)
counter presets to 12345 and changes counting direction
counter counts down from 12345 to 00000 (12345 clock cycles)

counter presets to 12345 and changes counting direction
counter counts from 12345 up to 65536 (53191 clockcycles)
counter presets to 12345 and changes counting direction
counter counts down from 12345 to 00000 (12345 clock cycles)
.
.
.

so direction is up in 53191/65536 clockcycles and down for
12345/65536 clockcycles   viola!!

hope it helps and works 8-)

-Lasse 
----------------------------------------------------------
Lasse Langwadt Christensen, M.Sc. EE (to be in 1999)
Aalborg University Department of control engineering      
e-mail: Fuz@control.auc.dk  web: http://www.control.auc.dk/~fuz 
snail-mail: Lobovej 20 - 9230 Svenstrup - Denmark
Phone: +45 4026 5572 (remove NOSPAM to reply)