Hot Socketing & Power-On Reset
If you cannot meet the maximum VCC ramp time requirement, you must
use an external component to hold nCONFIGlow until the power supplies
have reached their minimum recommend operating levels. Otherwise,
the device may not properly configure and enter user mode.
Cyclone II devices are hot socketable and support all power-up and
power-down sequences with the one requirement that VCCIO and VCCINT
be powered up and down within 100 ms of each other to keep the I/O
pins from driving out. Cyclone II devices do not require any external
devices for hot socketing and power sequencing.
Conclusion
Table 4–1 shows the revision history for this document.
Document
Revision History
Table 4–1. Document Revision History
Date &
Document
Version
Changes Made
Summary of Changes
February 2007
v3.1
●
●
Added document revision history.
Updated “I/O Pins Remain Tri-Stated during Power-Up”
section.
Updated “Power-On Reset Circuitry” section.
Added footnote to Figure 4–3.
●
Specified VCCIO and VCCINT
supplies must be GND
when "not powered".
Added clarification about
input-tristate behavior.
Added infomation on VCC
monotonic ramp.
●
●
●
●
July 2005 v2.0
Updated technical content throughout.
Removed ESD section.
February 2005
v1.1
June 2004 v1.0 Added document to the Cyclone II Device Handbook.
Altera Corporation
February 2007
4–7
Cyclone II Device Handbook, Volume 1
ALTERA [ ALTERA CORPORATION ]
