DOM MB Diagnosis page
Board ID:
Rev 5.0 SN 0
Source:
From Test Lab crew
Symptoms:
Communications failure at low
temperature, or boot problem.
Analyst(s):
Thorsten Stezelberger
Analysis Procedure(s):
Probing various status bits around the EPXA4 and the EPC8, while
operating at a temperature that induces the fault
condition. Study of data sheets. Trouble issue opened with
Altera for insight into the problem.
Root cause:
Race condition involving the
timing of nPOR delay with respect to the 3.3V or 1.8V core
voltage being applied to the EPXA4, and the start-up delay of the EPC8
configuration memory. The EPXA4 would momentarily display the
'loaded' state to the EPC8 memory causing it to go into a sleep
mode.
Mitigation:
An enhancement to the CPLD causes the unloaded state be presented to
the EPC8 during the time when the EPXA4 is in an uninitialized,
pre-loaded state.
Disposition:
Tests still under way.
Any Other Information:
Traveler