MCF5282 RESET Problem

[a8Chcx]

Hi,

It is Christie from Canada. I have the following problem:

When I power on MCF5282 or reset MCF5282, RSTO/ stays LOW. I tried to disable PLL(CLKMOD0,1-->GND) and use external CLK, it is same. I measure the CLK on EXTAL and XTAL, the EXTAL is about 0.928VDC, XTAL is about 0.738, but on 5282Lite board, EXTAL is about 0.684VDC, XTAL is about 0.832. Both have the CLKOUT.

Could somebody tell me where the problem could be?

Thank you very much.

Christie

[Neubie]

Hi - Search the User's Manual for XTAL - There is a NOTE on ONE page of the 782 pages that says that IF you are running in external clock mode, you must tie XTAL to GND during RESET or the internal clock 'may be suspended indefinitely'.  It is terrible that this note doesn't show up in the documentation EVERYWHERE that XTAL is referenced because who expects to have to tie an OUTPUT to GND for the part to operate properly.

I have also asked the question as to whether the XTAL pin can be grounded all the time to satisfy this requirement or if it needs to be released after RESET - it is unclear from the NOTE.

Hope this helps.