RES: GPIO

[Wendell Pereira da Silva]

Guilherme,

In this case (ERC-32), the GPIO configuration register is at 0x01F800A8, and the I/O register is 0x01F800AC. So, the following code fragment illustrates what you want to do:

#define GPIO_DATA_ADDR  (unsigned long *)0x01F800AC
#define GPIO_CONF_ADDR  (unsigned long *)0x01F800A8

rtems_task Init(...)
{
     // configure all GPIO pins as output
     *GPIO_CONF_ADDR = 0x00;

     // set bit GPIO[0] and clear other ones.
     *GPIO_DATA_ADDR = 0x01;

     // set bit GPIO[3] and leave others untouched.
     *GPIO_DATA_ADDR = *GPIO_DATA_ADDR | (1 << 3);
}

See the ERC32 datasheet for further details.
Also, there's a lot of good references on Embedded Development in the Internet.
A good one is the book: http://ebookee.org/Programming-Embedded-Systems-With-C-and-Gnu-Development-Tools-2nd-Edition_336503.html

Att.
Wendell.


De: rtems-users-bounces at rtems.org [mailto:rtems-users-bounces at rtems.org] Em nome de Guilherme Resende
Enviada em: segunda-feira, 23 de maio de 2011 10:45
Para: rtems-users at rtems.org
Assunto: GPIO


Hello everyone,
First of all, I would like to apologize if the level of my doubt is too low , but I am a newbie in the world of RTEMS and Embedded Programming.
What I've been trying to do ,  is to access the GPIO ports bit by bit, like, setting GPIO[7] through GPIO[1] as outputs
and GPIO[0] as an input.
Could anyone help me with that?
My embedded processor is Sparc ERC-32
Thanks!



Guilherme  Resende



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.rtems.org/pipermail/users/attachments/20110523/c0ca42d4/attachment-0001.html>