Configuration Handbook - Kamami.pl

Configuring APEX 20KE & APEX 20KC DevicesFigure 7–21. Multi-Device PPA Configuration Using a MicroprocessorV CC (2)(2) V CC10 kΩ10 kΩV CC (2)Address Decoder10 kΩADDRMemoryADDR DATA[7..0]10 kΩV CC (2)MicroprocessorAPEX 20KE orAPEX 20KC Device 1DATA[7..0] nCEnCS (1)CS (1)CONF_DONE DCLKnSTATUSnCEOnWSnRSnCONFIGRDYnBSYMSEL1MSEL0GNDV CCAPEX 20KE orAPEX 20KC Device 2DATA[7..0]DCLKnCS (1)CS (1)CONF_DONEnSTATUSnCEnCEOnWSnRSnCONFIG MSEL1RDYnBSY MSEL0N.C.V CCNotes to Figure 7–21:(1) If not used, the CS pin can be connected to V CC directly. If not used, the nCS pin can be connected to GND directly.(2) The pull-up resistor should be connected to a supply that provides an acceptable input signal for all devices in thechain.In multi-device PPA configuration the first device’s nCE pin is connectedto GND while its nCEO pin is connected to nCE of the next device in thechain. The last device’s nCE input comes from the previous device, whileits nCEO pin is left floating. After the first device completes configurationin a multi-device configuration chain, its nCEO pin drives low to activatethe second device’s nCE pin, which prompts the second device to beginconfiguration. The second device in the chain begins configuration withinone clock cycle; therefore, the transfer of data destinations is transparentto the microprocessor.Altera Corporation 7–47August 2005 Configuration Handbook, Volume 1