Configuring Cyclone II Devices
Table 13–11. Dedicated Configuration Pins on the Cyclone II Device (Part 4 of 5)
User Configuration
Pin Name
nCEO
Pin Type
Description
Mode
Scheme
N/A if
option
is on.
I/O if
All
Output
This pin is an output that drives low when device
configuration is complete. In single device
configuration, you can leave this pin floating or use it
as a user I/O pin after configuration. In multiple
device configuration, this pin inputs the next device's
nCEpin. The nCEOof the last device in the chain can
be left floating or used as a user I/O pin after
configuration.
option
is off.
If you use the nCEOpin to feed next device’s nCEpin,
use an external 10-kΩ pull-up resistor to pull the
nCEOpin high to the VCCIO voltage of its I/O bank to
help the internal weak pull-up resistor.
Use the Quartus II software to make this pin a user
I/O pin.
N/A in AS
AS
mode
I/O in
PS and
JTAG
Output
Output
This pin sends a control signal from the Cyclone II
device to the serial configuration device in AS mode
and is used to read out configuration data.
ASDO
nCSO
In AS mode, ASDOhas an internal pull-up that is
always active.
mode
N/A in AS
AS
mode
This pin sends an output control signal from the
Cyclone II device to the serial configuration device in
AS mode that enables the configuration device.
I/O in
PS and
JTAG
In AS mode, nCSOhas an internal pull-up resistor
that is always active.
mode
Altera Corporation
February 2007
13–67
Cyclone II Device Handbook, Volume 1
ALTERA [ ALTERA CORPORATION ]
