EP4SE360F35I4 Datasheet, PDF (375/432 Pages) Altera Corporation – This section provides a complete overview of all features relating to the Stratix IV device family, which is the most architecturlly advanced

Chapter 10: Configuration, Design Security, and Remote System Upgrades in Stratix IV Devices
JTAG Configuration
10–39
You must connect the nCE pin to GND or drive it low during JTAG configuration. In
multi-device FPP, AS, and PS configuration chains, the first device’s nCE pin is
connected to GND, while its nCEO pin is connected to nCE of the next device in the
chain. The last device’s nCE input comes from the previous device, while its nCEO pin is
left floating. In addition, the CONF_DONE and nSTATUS signals are all shared in
multi-device FPP, AS, or PS configuration chains so the devices can enter user mode at
the same time after configuration is complete. When the CONF_DONE and nSTATUS
signals are shared among all the devices, you must configure every device when JTAG
configuration is performed.
If you only use JTAG configuration, Altera recommends connecting the circuitry as
shown in Figure 10–17, where each of the CONF_DONE and nSTATUS signals are isolated,
so that each device can enter user mode individually.
After the first device completes configuration in a multi-device configuration chain,
its nCEO pin drives low to activate the second device’s nCE pin, which prompts the
second device to begin configuration. Therefore, if these devices are also in a JTAG
chain, ensure the nCE pins are connected to GND during JTAG configuration or that
the devices are JTAG configured in the same order as the configuration chain. As long
as the devices are JTAG configured in the same order as the multi-device
configuration chain, the nCEO of the previous device drives the nCE of the next device
low when it has successfully been JTAG configured.
You can place other Altera devices that have JTAG support in the same JTAG chain for
device programming and configuration.
1 JTAG configuration support is enhanced and allows more than 17 Stratix IV devices to
be cascaded in a JTAG chain.
f For more information about configuring multiple Altera devices in the same
configuration chain, refer to the Configuring Mixed Altera FPGA Chains chapter in
volume 2 of the Configuration Handbook.
You can configure Stratix IV devices using multiple configuration schemes on the
same board. Combining JTAG configuration with AS configuration on your board is
useful in the prototyping environment because it allows multiple methods to
configure your FPGA.
f For more information about combining JTAG configuration with other configuration
schemes, refer to the Combining Different Configuration Schemes chapter in volume 2 of
the Configuration Handbook.
September 2012 Altera Corporation
Stratix IV Device Handbook
Volume 1