[ECOS] Question about system bus

[harri.siirtola@vtt.fi]

At 17:31 18.6.2001 +0100, HuangQiang wrote:
>Hi all:
>...
>e.g.
>    reading from the ext IO
>
>	int k;
>	*EXTIOBANK0 = 1;
>	k = *EXTIOBANK0;
>	// now k is not the same as what I have written to ('1'). why ?

I don't know of EB7T exactly but in many processors, an I/O port defined as
an output is write-only. So you must maintain a static variable to hold the
last value written to the port. You said you're getting proper select
signals so I suppose your EXTIOBANK0 declaration is ok (otherwise the first
thing to check).

>
>Thank you
>
>huang

	Harri