68300

After further research, what I am doing appears to be fine.
A 1/3 drive can sink about 8-10 ma. A Full drive output can source up 
to about 60ma.
Connecting these together, and drive the Full high and the 1/3 low is 
limited by the 1/3 drive output to about 10ma. This is within pin 
limits.

On Apr 5, 2005, at 1:34 PM, Robert Yablonski wrote:

>
> Tim,
>
> I would not do this.  It creates a lot of noise on the board.  You are
> trying to force 100ma thru two pins on the processor.  The pins rated 
> at
> 10ma will source a lot more than 10ma. the same for the 1/3 drive
> pins.  You will not know what voltage is generated on either end of the
> resistor when the contention happens.
>
> Maybe there is some other solution to the design you are trying to 
> accomplish.
>
>
>
> At 08:06 AM 4/5/2005, you wrote:
>
>> Hello all,
>> This isn't actually a question about the 683xx, but for the 
>> HCS12DP256.
>> Some I/O pins have the capability of full (10ma) drive and 1/3 drive
>> settings.
>> What is the reliability of the processor if I drive a full drive pin 
>> to
>> VCC and connect it via a (approx) 50 ohm resistor to an other pin
>> driven low with 1/3 drive? This contention would last for ~ 200
>> microseconds out of a period of 40 milliseconds. 0.5% duty cycle
>> effectively.
>> Basically like an active pull down.
>>
>> or please point me in the correct direction.
>>
>> Tim Flynn
>>
>>
>>
>>
>> Yahoo! Groups Links
>>
>>
>>
>>
> Sincerely,
>
> Robert E. Yablonski
>
>
> Hunt Dabney & Associates
> Electronic System Development and Design
> 1366 Logan Ave, Suite B
> Costa Mesa, CA 92626
> --------------------------------------------------------------------
> http://www.huntdabney.com
> fax: (714) 540-8131
> 714 540-2372 X104
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>
Tim Flynn
Director of R&D
RMS Welding Systems
Ph.(780)955-3907
http://www.rmsweldingsystems.com