EP2AGX95EF29C6N Datasheet, PDF (327/380 Pages) Altera Corporation – Device Interfaces and Integration

Chapter 9: Configuration, Design Security, and Remote System Upgrades in Arria II Devices
Device Configuration Pins
9–41
Table 9–16. Dedicated Configuration Pins on the Arria II Device (Part 2 of 4)
Pin Name
nSTATUS
CONF_DONE
User Mode
Configuration
Scheme
Pin Type
Description
The device drives nSTATUS low immediately after power-up
and releases it after the POR time.
During user mode and regular configuration, this pin is
pulled high by an external 10-k resistor.
This pin, when driven low by the Arria II device, indicates
that the device has encountered an error during
configuration.
■ Status output—If an error occurs during configuration,
nSTATUS is pulled low by the target device.
■ Status input—If an external source drives the nSTATUS
pin low during configuration or initialization, the target
device enters an error state.
Driving nSTATUS low after configuration and initialization
does not affect the configured device. If you use a
configuration device, driving nSTATUS low causes the
configuration device to attempt to configure the device, but
N/A
All
Bidirectional _{because the device ignores transitions on nSTATUS in user}
open-drain _{mode, the device does not reconfigure. To begin a}
reconfiguration, nCONFIG must be pulled low.
If V_CCIO for Arria II GX devices or V_CCPGM for Arria II GZ
devices are not fully powered up, the following could occur:
■ V_CCIO/V_CCPGM is powered high enough for the nSTATUS
buffer to function properly and nSTATUS is driven low.
When V_CCIO/V_CCPGM is ramped up, POR trips and nSTATUS
is released after POR expires.
■ V_CCIO/V_CCPGM is not powered high enough for the nSTATUS
buffer to function properly. In this situation, nSTATUS
might appear logic high, triggering a configuration
attempt that fails because POR did not yet trip. When
V_CCPD is powered up, nSTATUS is pulled low because POR
did not yet trip. When POR trips after V_CCIO/V_CCPGM is
powered up, nSTATUS is released and pulled high. At that
point, reconfiguration is triggered and the device is
configured.
Status output. The target device drives the CONF_DONE pin
low before and during configuration. After all configuration
data is received without error and the initialization cycle
starts, the target device releases CONF_DONE.
N/A
All
Bidirectional Status input. After all data is received and CONF_DONE goes
open-drain high, the target device initializes and enters user mode. The
CONF_DONE pin must have an external 10-k pull-up
resistor for the device to initialize.
Driving CONF_DONE low after configuration and initialization
does not affect the configured device.
July 2012 Altera Corporation
Arria II Device Handbook Volume 1: Device Interfaces and Integration