EP2AGX95EF29C6N Datasheet, PDF (376/380 Pages) Altera Corporation – Device Interfaces and Integration

12–2
Chapter 12: Power Management in Arria II Devices
Hot Socketing
The POR circuitry monitors V_CC, V_CCAUX, V_CCCB, V_CCPGM, and V_CCPD supplies in
Arria II GZ devices. The POR circuitry keeps the Arria II GZ devices in reset state
until the power supply outputs are within operating range (provided that the V_CC
powers up fully before V_CCAUX).
POR circuitry is important to ensure that all the circuits in the Arria II device are at
certain known states during power up. You can select the POR signal pulse width
between fast POR time or standard POR time using the MSEL pin settings. For fast
POR time, the POR signal pulse width is set to 4 ms for the power supplies to ramp up
to full rail. For standard POR time, the POR signal pulse width is set to 100 ms for the
power supplies to ramp up to full rail. In both cases, you can extend the POR time
with an external component to assert the nSTATUS pin low.
f For more information about the POR specification, refer to the Device Datasheet for
Arria II Devices chapter.
f For more information about MSEL pin settings, refer to the Configuration, Design
Security, and Remote System Upgrades in Arria II Devices chapter.
Hot Socketing
Arria II I/O pins are hot-socketing compliant without the need for external
components or special design requirements. Hot-socketing support in Arria II devices
has the following advantages:
■ You can drive the device before power up without damaging the device.
■ I/O pins remain tri-stated during power up. The device does not drive out before
or during power-up. Therefore, it does not affect other buses in operation.
■ You can insert or remove an Arria II device from a powered-up system board
without damaging or interfering with normal system and board operation.
Devices Can Be Driven Before Power-Up
You can drive signals into regular Arria II I/O pins and transceiver before or during
power up or power down without damaging the device. Arria II devices support any
power-up or power-down sequence to simplify the system-level designs.
I/O Pins Remain Tri-Stated During Power-Up
A device that does not support hot socketing may interrupt system operation or cause
contention by driving out before or during power up. In a hot-socketing situation, the
Arria II output buffers are turned off during system power up or power down. Also,
the Arria II device does not drive out until the device is configured and working
within recommended operating conditions.
Arria II Device Handbook Volume 1: Device Interfaces and Integration
June 2011 Altera Corporation