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Altera_Forum's avatar
Altera_Forum
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17 years ago

Mixing Multi-device FPP configuration with JTAG

Hi,

could someone clear this up for me:

from SIII configuration manual:

"

On all Stratix III devices in the chain, nCE should be driven low

by connecting it to ground, pulling it low via a resistor, or driving

it by some control circuitry. For devices that are also in

multi-device FPP, AS, or PS configuration chains, the nCE pins

should be connected to GND during JTAG configuration or JTAG

configured in the same order as the configuration chain.

"

What does the last bit mean i.e. JTAG configured in the same order as the chain?

Is this simply a case of ordering the devices in the programming utility window so that they match the physical order?

Does this mean I can perform JTAG configuration as well has doing multi-device FPP where the CE pins are daisy-chained? Or, must I force the CE pins to ground when doing JTAG?

Thanks and regards,

Dave.

4 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    The Configuration Handbook mentions this point more than once: nCE must be held low during JTAG configuration. You have two options to achieve this: 1. Connect the pin to ground. 2, If it's connected to preceeding devices nCEO in multi device chain (may be AS, AP, PS or PP), this device must be configured before, cause nCEO will go low only after succesful configuration. configured in the same order means the actual sequence in time. If you want to program all devices in a single action, then this would be identical to the order in JTAG chain which is also the order in the programming window.

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    Thanks, but is the correct order that which is autodetected? (Because you can manually re-order following auto-detection).

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    The JTAG chain order may be different from the nCE chain order, autodetect is only related to JTAG.