Configuration Handbook - Kamami.pl

Device Configuration PinsTable 13–11. Dedicated Configuration Pins on the Cyclone II Device (Part 3 of 5)Pin NameUserModeConfigurationSchemePin TypeCONF_DONE N/A All Bidirectionalopen-drainDescriptionThis pin is a status output and input.The target Cyclone II device drives the CONF_DONEpin low before and during configuration. Once theCyclone II device receives all the configuration datawithout error and the initialization cycle starts, itreleases CONF_DONE. Driving CONF_DONE lowduring user mode does not affect the configureddevice. Do not drive CONF_DONE low before thedevice enters user mode.After the Cyclone II device receives all the data, theCONF_DONE pin transitions high, and the deviceinitializes and enters user mode. The CONF_DONEpin must have an external 10-kΩ pull-up resistor inorder for the device to initialize.Driving CONF_DONE low after configuration andinitialization does not affect the configured device.The enhanced configuration devices’ and EPC2devices’ OE and nCS pins are connected to theCyclone II device’s nSTATUS and CONF_DONE pins,respectively, and have optional internalprogrammable pull-up resistors. If internal pull-upresistors on the enhanced configuration device areused, external 10-kΩ pull-up resistors should not beused on these pins. When using EPC2 devices, youshould only use external 10-kΩ pull-up resistors.The input buffer on this pin supports hysteresis usingSchmitt trigger circuitry.nCE N/A All Input This pin is an active-low chip enable. The nCE pinactivates the device with a low signal to allowconfiguration. The nCE pin must be held low duringconfiguration, initialization, and user mode. In singledevice configuration, it should be tied low. In multipledevice configuration, nCE of the first device is tied lowwhile its nCEO pin is connected to nCE of the nextdevice in the chain.The nCE pin must also be held low for successfulJTAG programming of the FPGA.The input buffer on this pin supports hysteresis usingSchmitt trigger circuitry.13–66 Altera CorporationCyclone II Device Handbook, Volume 1 February 2007