Easy way to test crystal with Boot Rom?

Rayman

Wish there was a page somewhere on how to do some simple tests of a board with the Boot ROM...

Had to search around (again) for the magic three key sequence to start it: > then , then ESC

Wanted to check the crystal but don't know how, or where to look to find out how...

But, at least it told me that the serial interface was OK. Does it have to be OK to download a program? I guess it does...

Anyway, I did figure out it had to be the crystal and sure enough soldering one the P2 pins connected to the crystal fixed the problem...

jmg

Rayman wrote: »

..
Wanted to check the crystal but don't know how, or where to look to find out how...

There is no alternate pathway for the Xtal into the P2 logic area, so the only way to 'check' it, is to select and hope...
ie confirm RCFAST is ok, using boot ROM, and then select XTAL and check you can still talk....as you did above.

( On the UB3, there is an EXTCLK/8 pathway, so there we can start a timer, and check it advances an expected amount, before select of EXTCLK as a clock source)

Rayman

Ok, so no way to check. Thanks.

I’m trying to remember the symptoms...

Think would not load with loadp2.
But, would identify and load with PNut.
But no serial output that was expected...