EP3C10U256C6N Datasheet, PDF (224/274 Pages) Altera Corporation – Cyclone III Device Family Overview

9–66
Chapter 9: Configuration, Design Security, and Remote System Upgrades in the Cyclone III Device Family
Configuration Features
Table 9–22 lists the dedicated configuration pins that must be connected properly on
your board for successful configuration. Some of these pins may not be required for
your configuration scheme.
Table 9–22. Dedicated Configuration Pins on Cyclone III Device Family (Part 1 of 4)
Pin Name
User
Mode
Configuration
Scheme
Pin Type
Description
MSEL [3..0]
N/A
nCONFIG
N/A
nSTATUS
N/A
CONF_DONE
N/A
4-bit configuration input that sets the Cyclone III device
family configuration scheme. These pins must be hardwired
to V_CCA or GND. The MSEL[3..0] pins have internal 9-k
All
Input ^{pull-down resistors that are always active.}
Some of the smaller devices or package options of
Cyclone III devices do not have the MSEL[3] pin; therefore,
the AP configuration scheme is not supported.
Configuration control input. Pulling this pin low with external
circuitry during user mode causes the Cyclone III device
All
Input family to lose its configuration data, enter a reset state, and
tri-state all I/O pins. Returning this pin to a logic-high level
starts a reconfiguration.
The Cyclone III device family drives nSTATUS low
immediately after power-up and releases it after the POR
time.
■ Status output. If an error occurs during configuration,
nSTATUS is pulled low by the target device.
■ Status input. If an external source (for example, another
Cyclone III device family) drives the nSTATUS pin low
All
Bidirectional
open-drain
during configuration or initialization, the target device
enters an error state.
Driving nSTATUS low after configuration and initialization
does not affect the configured device. If you use a
configuration device, driving nSTATUS low causes the
configuration device to attempt to configure the device, but
because the device ignores transitions on nSTATUS in user
mode, the device does not reconfigure. To start a
reconfiguration, nCONFIG must be pulled low.
■ Status output. The target Cyclone III device family drives
the CONF_DONE pin low before and during configuration.
After all configuration data is received without error and
the initialization cycle starts, the target device releases
CONF_DONE.
All
Bidirectional ■ Status input. After all data is received and CONF_DONE
open-drain 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 the CONF_DONE pin.
Cyclone III Device Handbook
Volume 1
August 2012 Altera Corporation