Configuration Handbook - Kamami.pl

Configuring Stratix II & Stratix II GX DevicesYou can cascade several EPC2 devices to configure multiple Stratix II orStratix II GX devices. The first configuration device in the chain is themaster configuration device, while the subsequent devices are the slavedevices. The master configuration device sends DCLK to the Stratix II orStratix II GX devices and to the slave configuration devices. The first EPCdevice’s nCS pin is connected to the CONF_DONE pins of the devices,while its nCASC pin is connected to nCS of the next configuration devicein the chain. The last device’s nCS input comes from the previous device,while its nCASC pin is left floating. When all data from the firstconfiguration device is sent, it drives nCASC low, which in turn drivesnCS on the next configuration device. A configuration device requiresless than one clock cycle to activate a subsequent configuration device, sothe data stream is uninterrupted.1 Enhanced configuration devices cannot be cascaded.Because all nSTATUS and CONF_DONE pins are tied together, if any devicedetects an error, the master configuration device stops configuration forthe entire chain and the entire chain must be reconfigured. For example,if the master configuration device does not detect CONF_DONE going highat the end of configuration, it resets the entire chain by pulling its OE pinlow. This low signal drives the OE pin low on the slave configurationdevice(s) and drives nSTATUS low on all devices, causing them to enter areset state. This behavior is similar to the device detecting an error in theconfiguration data.Altera Corporation 7–65May 2007 Stratix II Device Handbook, Volume 2