Chapter 8: Configuration and Remote System Upgrades in Cyclone IV Devices
8–65
Configuration
May 2013
Altera Corporation
CONF_DONE
N/A
All
Bidirectional
open-drain
■
Status output—the target Cyclone IV device drives the
CONF_DONE
pin low before and during configuration.
After all the configuration data is received without error
and the initialization cycle starts, the target device
releases
CONF_DONE.
■
Status input—after all the 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
pull-up resistor in order for the device to
initialize.
Driving
CONF_DONE
low after configuration and initialization
does not affect the configured device. Do not connect bus
holds or ADC to
CONF_DONE
pin.
nCE
N/A
All
Input
Active-low chip enable. The
nCE
pin activates the Cyclone
IV device with a low signal to allow configuration. You must
hold
nCE
pin low during configuration, initialization, and
user-mode. In a single-device configuration, you must tie
the
nCE
pin low. In a 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. You must hold the
nCE
pin low for successful JTAG programming of the device.
nCEO
N/A if
option is on.
I/O if option
is off.
All
Output
open-drain
Output that drives low when configuration is complete. In a
single-device configuration, you can leave this pin floating
or use it as a user I/O pin after configuration. In a multi-
device configuration, this pin feeds the
nCE
pin of the next
device. The
nCEO
of the last device in the chain is left
floating or used as a user I/O pin after configuration.
If you use the
nCEO
pin to feed the
nCE
pin of the next
device, use an external 10-k
pull-up resistor to pull the
nCEO
pin high to the V
CCIO
voltage of its I/O bank to help the
internal weak pull-up resistor.
If you use the
nCEO
pin as a user I/O pin after configuration,
set the state of the pin on the
Dual-Purpose Pin
settings.
nCSO
,
FLASH_nCE
I/O
AS, AP
Output
Output control signal from the Cyclone IV device to the
serial configuration device in AS mode that enables the
configuration device. This pin functions as
nCSO
in AS
mode and
FLASH_nCE
in AP mode.
Output control signal from the Cyclone IV device to the
parallel flash in AP mode that enables the flash. Connects to
the
CE#
pin on the Micron P30 or P33 flash.
This pin has an internal pull-up resistor that is always
active.
Table 8–20. Dedicated Configuration Pins on the Cyclone IV Device (Part 2 of 4)
Pin Name
User Mode
Configuration
Scheme
Pin Type
Description
Summary of Contents for Cyclone IV
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