Altera Corporation
11–59
July 2005
Stratix Device Handbook, Volume 2
Configuring Stratix & Stratix GX Devices
Table 11–16 describes 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-ups.
Table 11–16. Optional Configuration Pins
Pin Name
User Mode
Pin Type
Description
CLKUSR
N/A if option is
on. I/O if option
is off.
Input
Optional user-supplied clock input. Synchronizes the
initialization of one or more devices. This pin is enabled by
turning on the Enable user-supplied start-up clock
(CLKUSR) option in the Quartus II software.
INIT_DONE
N/A if option is
on. I/O if option
is off.
Output open-
drain
Status pin. Can be used 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
Ω pull-up.
Once 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 FPGA enters user mode. Thus, the monitoring
circuitry must be able to detect a low-to-high transition. This
pin is enabled by turning on the Enable INIT_DONE output
option in the Quartus II software.
DEV_OE
N/A if option is
on. I/O if option
is off.
Input
Optional pin that allows the user to override all tri-states on
the device. When this pin is driven low, all I/Os are tri-stated.
When this pin is driven high, all I/Os behave as programmed.
This pin is enabled by turning on the Enable device-wide
output enable (DEV_OE) option in the Quartus II software.
DEV_CLRn
N/A if option is
on. I/O if option
is off.
Input
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. This pin is enabled by turning on the Enable
device-wide reset (DEV_CLRn) option in the Quartus II
software.