TLL Logic? reading 3.3v on a pin?

[dhouston]

Porta.4 which is an Schmitt trigger input reads the low voltage just fine...

I would expect more trouble with the Schmitt trigger which requires 0.8*Vdd or 4V for logic high.

Anyway, I usually use the circuits shown in FIG 13 or FIG 14 in this App Note http://www.zbasic.net/appNotes/AN213.pdf

[RFEFX]

I would expect more trouble with the Schmitt trigger which requires 0.8*Vdd or 4V for logic high.

i agree but found that the following works well with it.

IF porta.4 != 0 then <label>

Thnx for your help guys

[BigWumpus]

Forget all this TTL-things !
You are in the CMOS-decade !!!!

No one is using TTL-Logic !!!!

Just look in the datasheet and look at the functions of each post-pin !! there is a lot of surprise !!!