The Texas Instruments site is one of the best free sites that I've come across.

http://www.ti.com/sc/docs/jtag/jtaghome.htm

In specific, if you are new to JTAG, I would recommend the following document.

http://www-s.ti.com/sc/psheet...ya002c.pdf

I'm with you. I don't understand why IEEE doesn't make the JTAG spec. available as a downloadable PDF. Oh yeah, they think they're adding value by charging for it.

What are you hoping to do with the E5 device? If you're interested in some advanced debugging, the Triscend development tools also allow you to drive the JTAG connection via the command line or a batch file.

To write the value 0xA5 to the SCON register via JTAG, type the following command at the DOS prompt followed by the Enter key.
<blockquote>
csoc writereg scon=0xa5 –xref <xref_file>
</blockquote>
The cross-reference file, *.xref, is created by FastChip when you create the original CSoC configuration image. The *.xref file contains all the observable items within the current design.

Likewise, to read the SCON register, type the following command at the DOS prompt, followed by the Enter key.
<blockquote>
csoc readreg scon:[<radix>] –xref <xref_file>
</blockquote>
The radix option formats the value read. Available options include<p>

• 2=binary,
• 8=octal,
• 10=decimal, and
• 16=hexadecimal.

By default, the return value is displayed in hexadecimal.

To obtain a full list of the “csoc debug” capabilities, type the following at the DOS prompt, again followed by the Enter key.
<blockquote>
csoc help debug
</blockquote>
For a complete manual listing for “csoc debug”, type the following at the DOS prompt, followed by the Enter key.
<blockquote>
csoc man debug
</blockquote>