Does Xilinx's step1 chips is the ES?

ES is usually Step 0, but there are several die runs for each step, sometimes there is JTAG ID code change also, sometimes not.

both ES (step 0) and non ES LX25 silicon works ok, we have used both

the stepping doesnt mean that the earlier silicon has bugs, it has some behaviour that is explained in the documents and errata, if that issues have been taked care then a bitstream for lower stepping will be compatible with no changes in later stepping.

well there are a few exceptions, where the ES bitstreams are not fully upwards compatible.

from step 1, and above the compatibility is maintained ASFAIK

Antti

Jude,

ES marking implies that the:

-test program is not final (parts are almost ready for production release) or

-the verification and characterization is not complete (early silicon, not all errata are known, or there is still work to do to characterize the parts) or

-the part is from a lot that has not finished process qualification (also early silicon, but all process qual tests may still be incomplete)

Once we have the final test program coverage we require, and the verification and characterization os signed off, and the process qualification is complete, then we stop marking parts as "ES."

Stepping relates to the features. Stepping 1 may have more features than stepping 0 (and may also have fewer errata, or no errata at all).

The stepping program makes it such that a newer stepping is backward (bitstream) compatible with an older stepping (the old bitstream provides the same performance). To gain the new features, a new bitstream may be required.

Austin

hi dears: OK, I see! Thank you very much!

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