[Coco] 6809 FPGA Success

[Mark McDougall]

On 29/09/2015 12:59 PM, Bill Nobel wrote:

> Most of the time when I program the Nano, I get a flaky VGA, it flashes
> the image in and out.  When i get the image I can see what I typed, but
> very unstable display, until I get a good programming that boots
> properly.

The other hint is that it fails the same way each time. Points to a design 
issue.

Occasionally you do get bad configuration cycles and it will always fail in 
Quartus when downloading - never executing a bad design. You can actually 
fry hardware doing that, so they try to make it unlikely.

Actually, does your PLL have a synchronous reset fed to it (see my other 
post). That could be the problem with flaky video...

The only other thing I can think of - and this is a long shot - is an 
invalid device config option in the setup, but can't think of a for-instance 
atm.

Regards,

-- 
|              Mark McDougall                | "Electrical Engineers do it
|  <http://members.iinet.net.au/~msmcdoug>   |   with less resistance!"