Answers Database

XC4000XL/XLT: Differences between the 4000XL and 4000XLT


Record #3077

Problem Title:
XC4000XL/XLT: Differences between the 4000XL and 4000XLT


Problem Description:
Urgency: standard

Keywords: PCI, 4000XL, 4000XLT, CLAMP DIODE

Description

The following is the  difference between 4000XL and 4000XLT parts


Solution 1:

The 4000XLT have a functional VTT pin that enables a clamp diode to VT that
protects the IOs as required by the PCI spec. In fact the PCI spec
specifies the IOs have a clamp diode connected to 3.3V besides the clamp
diode connected to GND (all 4000X devices have a clamp diode connected to
GND).
This product was introduced to meet the PCI requirements for clamp diodes
in the IOs.
Keep in mind the 4000XLT and the 4000XL devices are architecturally
identical and their configuration bitstreams are compatible as well.



End of Record #3077