Configuration Handbook - Kamami.pl

Fast Passive Parallel ConfigurationfFor more information on how to create configuration files formulti-device configuration chains, refer to the Software Settings chapterin volume 2 of the Configuration Handbook.In multi-device FPP 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. All other configuration pins (nCONFIG, nSTATUS, DCLK,DATA[7..0], and CONF_DONE) are connected to every device in thechain. Pay special attention to the configuration signals because they mayrequire buffering to ensure signal integrity and prevent clock skewproblems. Ensure that the DCLK and DATA lines are buffered for everyfourth device.When configuring multiple devices, configuration does not begin until alldevices release their OE or nSTATUS pins. Similarly, since all deviceCONF_DONE pins are tied together, all devices initialize and enter usermode at the same time.Since all nSTATUS and CONF_DONE pins are tied together, if any devicedetects an error, configuration stops for the entire chain and you mustreconfigure the entire chain. For example, if the first device flags an erroron nSTATUS, it resets the chain by pulling its nSTATUS pin low. This lowsignal drives the OE pin low on the enhanced configuration device anddrives nSTATUS low on all devices, which causes them to enter a resetstate. This behavior is similar to a single device detecting an error.If the Auto-restart configuration after error option is turned on, thedevices will automatically initiate reconfiguration if an error occurs. Thedevices will release their nSTATUS pins after a reset time-out period(maximum of 100 ms). When all the nSTATUS pins are released andpulled high, the configuration device tries to reconfigure the chain. If theAuto-restart configuration after error option is turned off, the externalsystem must monitor nSTATUS for errors and then pulse nCONFIG lowfor at least 2 ms to restart configuration. The external system can pulsenCONFIG if nCONFIG is under system control rather than tied to V CC .Your system may have multiple devices that contain the sameconfiguration data. To support this configuration scheme, all device nCEinputs are tied to GND, while nCEO pins are left floating. All otherconfiguration pins (nCONFIG, nSTATUS, DCLK, DATA[7..0], andCONF_DONE) are connected to every device in the chain. Configurationsignals may require buffering to ensure signal integrity and prevent clockskew problems. Ensure that the DCLK and DATA lines are buffered for11–28 Altera CorporationStratix III Device Handbook, Volume 1 May 2007