RES: write data to the address (PC104)

Wendell Pereira da Silva wendell.silva at
Thu Jun 28 14:08:22 UTC 2012

Just a tip: dont' forget to mark the pointer as 'volatile':
volatile unsigned char* addr = (volatile unsigned char*)0xD0000000; 
or, even better (#include <stdint.h>):
volatile uint8_t addr = (volatile uint8_t*)0xD0000000; 

Since this is supposed to be an I/O addrees, you want to take the compiler's optimizer out of the way in this case.
De: rtems-users-bounces at [rtems-users-bounces at] em Nome de Joel Sherrill [joel.sherrill at]
Enviado: quinta-feira, 28 de junho de 2012 8:45
Para: zhoupeng; rtems-users
Assunto: Re: write data to the address (PC104)

Are you sure the device is in memory space and not I/O space?

If you can share the name of the card with a link, we can double check you.


zhoupeng <zpeng563 at> wrote:

>I am writing a device driver for PC104. I want to write data to the address (D0000). Can I use these code:
>unsigned char *address = (unsigned char *)0xD0000000;
>Thank you!

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