Configuration Handbook - Kamami.pl

Passive Serial ConfigurationYou can use a download cable to configure multiple APEX 20KE andAPEX 20KC devices by connecting each device’s nCEO pin to thesubsequent device’s nCE pin. The first device’s nCE pin is connected toGND while its nCEO pin is connected to the nCE of the next device in thechain. The last device’s nCE input comes from the previous device, whileits nCEO pin is left floating. All other configuration pins, nCONFIG,nSTATUS, DCLK, DATA0, and CONF_DONE are connected to every devicein the chain. Because all CONF_DONE pins are tied together, all devices inthe chain initialize and enter user mode at the same time.In addition, because the nSTATUS pins are tied together, the entire chainhalts configuration if any device detects an error. The Auto-RestartConfiguration After Error option does not affect the configuration cyclebecause you must manually restart configuration in the Quartus IIsoftware when an error occurs.Figure 7–14 shows how to configure multiple APEX 20KE andAPEX 20KC devices with a download cable.7–30 Altera CorporationConfiguration Handbook, Volume 1 August 2005