Configuration Handbook - Kamami.pl

Device Configuration PinsTable 7–23 describes the optional configuration pins. If these optionalconfiguration pins are not enabled in the Quartus II software, they areavailable as general-purpose user I/O pins. Therefore, duringconfiguration, these pins function as user I/O pins and are tri-stated withweak pull-up resistors.Table 7–23. Optional Configuration PinsPin Name User Mode Pin Type DescriptionCLKUSR N/A if option is on.I/O if option is off.Input Optional user-supplied clock input synchronizes theinitialization of one or more devices. This pin isenabled by turning on the Enable user-suppliedstart-up clock (CLKUSR) option in the Quartus IIsoftware.INIT_DONEDEV_OEDEV_CLRnN/A if option is on.I/O if option is off.N/A if option is on.I/O if option is off.N/A if option is on.I/O if option is off.Output open-drainInputInputStatus pin can be used to indicate when the devicehas initialized and is in user mode. When nCONFIG islow and during the beginning of configuration, theINIT_DONE pin is tri-stated and pulled high due toan external 10-kΩ pull-up resistor. Once the option bitto enable INIT_DONE is programmed into the device(during the first frame of configuration data), theINIT_DONE pin will go low. When initialization iscomplete, the INIT_DONE pin will be released andpulled high and the device enters user mode. Thus,the monitoring circuitry must be able to detect alow-to-high transition. This pin is enabled by turningon the Enable INIT_DONE output option in theQuartus II software.Optional pin that allows the user to override alltri-states on the device. When this pin is driven low, allI/O pins are tri-stated; when this pin is driven high, allI/O pins behave as programmed. This pin is enabledby turning on the Enable device-wide output enable(DEV_OE) option in the Quartus II software.Optional pin that allows you to override all clears onall device registers. When this pin is driven low, allregisters are cleared; when this pin is driven high, allregisters behave as programmed. This pin is enabledby turning on the Enable device-wide reset(DEV_CLRn) option in the Quartus II software.7–104 Altera CorporationStratix II Device Handbook, Volume 2 May 2007