Configuration Handbook - Kamami.pl

Configuring Stratix II & Stratix II GX DevicesWhen nSTATUS is pulled high, the configuration device’s OE pin alsogoes high and the configuration device clocks data out to the device usingthe Stratix II or Stratix II GX device’s internal oscillator. The Stratix II andStratix II GX devices receive configuration data on the DATA[7..0] pinsand the clock is received on the DCLK pin. A byte of data is latched intothe device on each 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 a pull-upresistor. Because CONF_DONE is tied to the configuration device’s nCS pin,the configuration device is disabled when CONF_DONE goes high.Enhanced configuration devices have an optional internal pull-upresistor on the nCS pin. This option is available in the Quartus II softwarefrom the General tab of the Device & Pin Options dialog box. If thisinternal pull-up resistor is not used, an external 10-kΩ pull-up resistor onthe nCS-CONF_DONE line is required. A low to high transition onCONF_DONE indicates configuration is complete and initialization of thedevice 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 the internal oscillator is used, the Stratix II or Stratix II GX deviceprovides 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. The Enable user-suppliedstart-up clock (CLKUSR) option can be turned on in the Quartus IIsoftware from the General tab of the Device & Pin Options dialog box.Supplying a clock on CLKUSR will not affect the configuration process.After all configuration data has been accepted and CONF_DONE goes high,CLKUSR will be enabled after the time specified as t CD2CU . After this timeperiod elapses, Stratix II and Stratix II GX devices require 299 clock cyclesto initialize properly and enter user mode. Stratix II and Stratix II GXdevices support a CLKUSR f MAX of 100 MHz.An optional INIT_DONE pin is available, which signals the end ofinitialization and the start of user-mode with a low-to-high transition.The Enable INIT_DONE Output option is available in the Quartus IIsoftware from the General tab of the Device & Pin Options dialog box.If the INIT_DONE pin is used, it will be high due to an external 10-kΩpull-up resistor when nCONFIG is low and during the beginning ofconfiguration. Once the option bit to enable INIT_DONE is programmedinto the device (during the first frame of configuration data), theINIT_DONE pin will go low. When initialization is complete, theINIT_DONE pin will be released and pulled high. In user-mode, the userAltera Corporation 7–29May 2007 Stratix II Device Handbook, Volume 2