
11–54
Altera Corporation
Stratix Device Handbook, Volume 2
July 2005
Device Configuration Pins
CONF_DONE
N/A
All
Bidirectional
open-drain
Status output. The target FPGA drives the
CONF_DONE
pin low before and during
configuration. Once all configuration data is
received without error and the initialization
cycle starts, the target device releases
CONF_DONE
.
Status input. After all data is received and
CONF_DONE
goes high, the target device
initializes and enters user mode. The
CONF_DONE pin must have an external
10-k
Ωpull-up resistor in order for the device to
initialize.
Driving CONF_DONE low after configuration
and initialization does not affect the configured
device.
The enhanced configuration devices’ and
EPC2 devices’ OE and nCS pins have optional
internal programmable pull-up resistors. If
internal pull-up resistors on the enhanced
configuration device are used, external 10-k
Ω
pull-up resistors should not be used on these
pins. When using EPC2 devices, only external
10-k
Ω pull-up resistors should be used.
This pin uses Schmitt trigger input buffers.
nCE
N/A
All
Input
Active-low chip enable. The nCE pin activates
the device with a low signal to allow
configuration. The nCE pin must be held low
during configuration, initialization, and user
mode. In single device configuration, it should
be tied low. In multi-device configuration, nCE
of the first device is tied low while its nCEO pin
is connected to nCE of the next device in the
chain.
The nCE pin must also be held low for
successful JTAG programming of the FPGA.
This pin uses Schmitt trigger input buffers.
Table 11–15. Dedicated Configuration Pins on the Stratix or Stratix GX Device
(Part 4 of 8)
Pin Name
User Mode
Configuration
Scheme
Pin Type
Description