[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: read 5V signal on parport0



To further clarify Magnus' answer: The parallel port signals on the 
ETRAX 100LX are 5 V-tolerant. It is therefore safe to apply 5 V signals
on them. On top of that, the par port inputs are protected with 4.7 kOhm
resistors on the dev. board.

Per Zander

On Mon, 27 Oct 2003, Magnus Mårtensson wrote:

> Hi.
> We have connected 5V logic to par0 in the past so it is safe. You can connect the 
> the 5V output from the LCD to ack_, busy_ paper_error for instance. As you can se in the schematics
> there is 4k7 ohm between the inputs and ETRAX.
> 
> Regards
> /Magnus
> 
>  
> > -----Original Message-----
> > From: Henrik Jönsson [mailto:henke@xxxxxxx.se]
> > Sent: den 24 oktober 2003 18:39
> > To: dev-etrax
> > Subject: read 5V signal on parport0
> > 
> > 
> > Hey ya
> > 
> > We have connected a LCD with a T6963C-controller to par0 (devboard 82,
> > 2.4.20) and we are writing a driver for this LCD. Is it safe 
> > to read the
> > busyflags of the LCD? I mean the parport is 3.3V and the 
> > display outputs
> > 5V. Is there any risk of breaking something?
> > 
> > Regards Henke
> > 
> > 
>