Answers Database

M1 TRCE: How does TRCE calculate worst case timing values if it is unaware of the temperature grade for a part?


Record #2945

Product Family:  Software

Product Line:  FPGA Implementation

Problem Title:
M1 TRCE: How does TRCE calculate worst case timing values if it is
unaware of the temperature grade for a part?



Problem Description:
Keywords: temperature grade, worst case, timing, speed

Urgency: standard

General Description:
TRCE: How does TRCE calculate worst case timing values if it is
unaware of the temperature grade for a part?


Solution 1:

The military grade part with the same speed grade as the commercial grade part i
s actually faster when both parts run at the same temperature.

For any given temperature grade part, we guarantee that it
will perform according to the worst case delays indicated
in the speeds file when operated at its upper temperature
limit.

A higher temperature grade part (say a military grade
part) will run up to the same speed at the the maximum
military temperature limit that a lower temperature grade
(say, commercial grade) part will run at, at its lower,
maximum temperature limit.  If we took the military grade
part and ran it at the commercial temperature limit, it
would be faster than the commercial grade part at that
temperature.

The Xilinx timing and simulation models guaranteed under
the following worst case conditions:

Voltage:  5 volts -5% for commercial grade
	  5 volts -10% for industrial and military grade

Temperature:  +85C junction temperature for commercial grade
	      +100C junction temperature for industrial grade
	      +125C case temperature for military grade

Output Loading:  50 pF



End of Record #2945