Configuration Handbook - Kamami.pl

Configuration Schemesdefault, the INIT_DONE output is disabled. You can enable theINIT_DONE output by turning on the Enable INIT_DONE outputoption in the Quartus II software.If you do not turn on the Enable INIT_DONE output option in theQuartus II software, you are advised to wait for maximum value oft CD2UM (see Table 11–9) after the CONF_DONE signal goes high to ensurethe device has been initialized properly and that it has entered user mode.During configuration and initialization and before the device enters usermode, the microprocessor must not drive the CONF_DONE signal low.1 If the optional CLKUSR pin is used and nCONFIG is pulled lowto restart configuration during device initialization, you need toensure CLKUSR continues toggling during the time nSTATUS islow (maximum of 40 µs).If the Stratix or Stratix GX device detects an error during configuration, itdrives nSTATUS low to alert the microprocessor. The pin on themicroprocessor connected to nSTATUS must be an input. Themicroprocessor can then pulse nCONFIG low to restart the configurationerror. With the Auto-restart configuration after error option on, theStratix or Stratix GX device releases nSTATUS after a reset time-outperiod. After nSTATUS is released, the microprocessor can reconfigurethe Stratix or Stratix GX device without pulsing nCONFIG low.The microprocessor can also monitor the CONF_DONE and INIT_DONEpins to ensure successful configuration. If the microprocessor sends allthe data and the initialization clock starts but CONF_DONE andINIT_DONE have not gone high, it must reconfigure the Stratix orStratix GX device. After waiting the specified 136 DCLK cycles, themicroprocessor should restart configuration by pulsing nCONFIG low.Figure 11–12 shows the circuit for Stratix and Stratix GX parallelconfiguration using a microprocessor.11–26 Altera CorporationStratix Device Handbook, Volume 2 July 2005