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Re: [N8VEM: 14672] Re: SBC V2 build not working

OK, good to see some progress.

Here are some more to try..

Enter C3 00 00  starting at location 0. This is a simple jump to location 0.

You should only have the first two (A0,A1) address lines wiggling and no others.  Also the CS for the Flash will also be wiggling (very fast)

Now try some reads from IO space.

Enter DB 6F C3 00 00 starting at location 0.  This will constantly read the UART's scratch register.  You should see the UART's CS wiggling (U6A pin 5 or U1 Pin 14)
 
Then you can move on to the RAM.  Remember, that at power on the ROM overlays the RAM up to 32K so start your writes at 0x8000


Cheers!

Max

On Wed, Sep 19, 2012 at 8:35 PM, opticpow <wa...@ingram.net.au> wrote:

Ok, tried Max's great suggestions. The 76 HALT instruction worked, I immediately got the red led after reset each time.

With the NOP, i'm pretty sure thats ok too. This grab is off the first 4 address lines. Hmm, this problem might justify a logic probe :)

I'm guessing if the flash is being read ok, problem must lie with RAM or the UART?

Wayne.






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