[ECOS] Question about system bus

[harri.siirtola@vtt.fi]

At 09:32 19.6.2001 +0100, HuangQiang wrote:
>But in the source code there "k!=1" ( I check it using the debuger). So if I
>want to read a data from a memory location how can I use it?
>  by "k = *EXTIOBANK0" or other means?
>When I write the data to the external memory location by "*EXTIOBANK0 = 1" ,
>I can get the CS signal for ext io bank0, while read I can't get the CS
>signal, why? Thank you
>huang

If this really is an I/O port, configuring it as inputs before reading
might be worth trying. Your processor may provide select signals according
to I/O configuration. Of course, in this case you're not getting what you
wrote just before but the states of the input lines (maybe random if not
connected to anything). Anyway, you could test if you get a select signal
like this. BTW, have you connected a FIFO or something to the port? In that
case, you could get what you wrote before...

	Harri