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Re: Gpio ports



There are three gpio ports, Port A, Port B, and Port G.  A and B are multiplexed
with the parrallel and serial ports, and port G allows you to access any unused
digital I/O pin on the board.  You should be able to use the parport pins with
the gpio driver.  

Look at ETRAX100LX Design Reference
(http://developer.axis.com/doc/hardware/etrax100lx/des_ref.html) for the
details.  Chapter 17 describes use of the port  and Chapter 20.10 describes how
the pins are multiplexed on the chip to the different I/O interfaces.  The MCM
chip on the Axis82 has almost the same pin out as the 100LX.  Then look at the
schematic for the Axis82 board
(http://developer.axis.com/doc/hardware/devboard_82/19227r2_schema.pdf) to
determine which pins you need and which you can use for gpio.


Robert Hibberdine wrote:
> 
> Hello,
> 
> I need 8 input ports on the Axis 82 board to monitor pulses from relays.
> The gpio driver seems to do the sort of thing I want but I am not sure
> where the gpio pins are. Forgive me if I've missed something obvious.
> 
> I understand that some of the gpio pins are used for the serial control
> lines etc. Are there any gpio pins that are just for gpio? I don't want
> to give up any of the serial ports.... Could I use the parport pins with
>    a gpio-like driver?
> 
> One final question. What is the time between each timer interrupt in the
> gpio driver?
> 
> Many thanks
> 
> Bob Hibberdine