Configuration Handbook - Kamami.pl

Configuring Stratix II & Stratix II GX DevicesWhen the power supplies have reached the appropriate operatingvoltages, the target device senses the low-to-high transition on nCONFIGand initiates the configuration cycle. The configuration cycle consists ofthree stages: reset, configuration, and initialization. While nCONFIG ornSTATUS are low, the device is in reset. The beginning of configurationcan be delayed by holding the nCONFIG or nSTATUS pin low.1 To begin configuration, power the V CCINT , V CCIO , and V CCPDvoltages (for the banks where the configuration and JTAG pinsreside) to the appropriate voltage levels.When nCONFIG goes high, the device comes out of reset and releases thenSTATUS pin, which is pulled high by a pull-up resistor. Enhancedconfiguration and EPC2 devices have an optional internal pull-up resistoron the OE pin. This option is available in the Quartus II software from theGeneral tab of the Device & Pin Options dialog box. If this internalpull-up resistor is not used, an external 10-kΩ pull-up resistor on theOE-nSTATUS line is required. Once nSTATUS is released, the device isready to receive configuration data and the configuration stage begins.When nSTATUS is pulled high, OE of the configuration device also goeshigh and the configuration device clocks data out serially to the deviceusing the Stratix II or Stratix II GX device’s internal oscillator. TheStratix II and Stratix II GX devices receive configuration data on theDATA0 pin and the clock is received on the DCLK pin. Data is latched intothe device on the rising edge of DCLK.After the device has received all configuration data successfully, itreleases the open-drain CONF_DONE pin, which is pulled high by apull-up resistor. Since CONF_DONE is tied to the configuration device’snCS pin, the configuration device is disabled when CONF_DONE goeshigh. Enhanced configuration and EPC2 devices have an optionalinternal pull-up resistor on the nCS pin. This option is available in theQuartus II software from the General tab of the Device & Pin Optionsdialog box. If this internal pull-up resistor is not used, an external 10-kΩpull-up resistor on the nCS-CONF_DONE line is required. A low-to-hightransition on CONF_DONE indicates configuration is complete andinitialization of the device can begin.In Stratix II and Stratix II GX devices, the initialization clock source iseither the internal oscillator (typically 10 MHz) or the optional CLKUSRpin. By default, the internal oscillator is the clock source for initialization.If you are using internal oscillator, the Stratix II or Stratix II GX devicesupplies itself with enough clock cycles for proper initialization. You alsohave the flexibility to synchronize initialization of multiple devices or todelay initialization with the CLKUSR option. You can turn on the Enableuser-supplied start-up clock (CLKUSR) option in the Quartus IIAltera Corporation 7–57May 2007 Stratix II Device Handbook, Volume 2