EP2AGX95EF29C6N Datasheet, PDF (330/380 Pages) Altera Corporation – Device Interfaces and Integration

9–44
Chapter 9: Configuration, Design Security, and Remote System Upgrades in Arria II Devices
Device Configuration Pins
Table 9–17 lists the optional configuration pins. If these optional configuration pins
are not enabled in the Quartus II software, they are available as general-purpose user
I/O pins. Therefore, during configuration, these pins function as user I/O pins and
are tri-stated with weak pull-up resistors.
Table 9–17. Optional Configuration Pins
Pin Name
User Mode
Pin Type
CLKUSR
N/A if option is on.
I/O if option is off.
Input
INIT_DONE
N/A if option is on.
I/O if option is off.
Output
open-drain
DEV_OE
N/A if option is on.
I/O if option is off.
Input
DEV_CLRn
N/A if option is on.
I/O if option is off.
Input
Description
Optional user-supplied clock input synchronizes the
initialization of one or more devices. Enable this pin by turning
on the Enable user-supplied start-up clock (CLKUSR) option
in the Quartus II software.
Use as a status pin to indicate when the device has initialized
and is in user mode. When nCONFIG is low and during the
beginning of configuration, the INIT_DONE pin is tri-stated
and pulled high due to an external 10-k pull-up resistor.
After the option bit to enable INIT_DONE is programmed into
the device (during the first frame of configuration data), the
INIT_DONE pin goes low. When initialization is complete, the
INIT_DONE pin is released and pulled high and the device
enters user mode. Thus, the monitoring circuitry must be able
to detect a low-to-high transition. Enable this pin by turning
on the Enable INIT_DONE output option in the Quartus II
software.
Optional pin that allows you to override all tri-states on the
device. When this pin is driven low, all I/O pins are tri-stated.
When this pin is driven high, all I/O pins behave as
programmed. Enable this pin by turning on the Enable
device-wide output enable (DEV_OE) option in the Quartus II
software.
Optional pin that allows you to override all clears on all device
registers. When this pin is driven low, all registers are cleared.
When this pin is driven high, all registers behave as
programmed. Enable this pin by turning on the Enable
device-wide reset (DEV_CLRn) option in the Quartus II
software.
Arria II Device Handbook Volume 1: Device Interfaces and Integration
July 2012 Altera Corporation