How do I parse a JED file?

[mavo]

Hi,

I need to develop software which can program / erase a XC9500 CPLD using JTAG. I have a JED file, and i have the JTAG communcations up and running and can read the ID code of the XC9500 device.

How do i parse a .JED file? or how to interpret the file so i can run the appropriate JTAG commands?

I am also unable to locate the correct JTAG programming specifications from Xilinx.

Basically i need:
1) A .JED file parser and
2) XC9500 JTAG programming specifications.

Where to look?

Thank you.

 

[echo47]

jed file

I haven't seen exactly what you are looking for, but this looks relevant to your question #2:
"XAPP058 - Xilinx In-System Programming Using an Embedded Microcontroller"
**broken link removed**

Other XC9500 info:
**broken link removed**

Other JTAG info:
**broken link removed**

 

[mavo]

jed format

Thanks for the help but i have already tried searching on these pages and reading the appnotes on the matter. But i dont seem to be able to find any specifications on the .JED file format and also no specifications on which JTAG commands to use for programming the CPLD.

Im not sure how to set up the address and data to load into the CPLD using JTAG.

It must have something to do with the ISPEN and FPGM commands to do.

Any comments on how to program binary data to a 2MB flash using JTAG would also be appreciated.

 

[echo47]

.jed file format

Yeah, those Xilinx documents didn't look totally satisfying to me either. Did you explore the JEDEC-to-SVF-to-XSVF-to-JTAG conversion steps? Maybe that's easier than trying to go directly JEDEC-to-JTAG.

This may be a good time to ask Xilinx. They usually respond to a WebCase within one or two business days. Registration is free.
https://www.xilinx.com/support/clearexpress/websupport.htm

Don't be surprised if some programming info is Xilinx confidential.

I think this is the JED format spec. Maybe it'll help a little:
https://www.jedec.org/download/search/jesd3c.pdf

I vaguely recall seeing some free JTAG programming utilities on the web. Maybe you can find one that includes source code, and examine it. Just a wild guess.

Can anyone else help?

 

[mavo]

jed file format

Thank you for the information.

I have now registered for a webcase and im awaiting approval. I will then ask Xilinx for some help.

I will try and read the jesd3c pdf, perhaps this will shed some light on the matter.

I think you are right that it might complicate things trying to go from JED to JTAG in one step, because the .JED file itself is confusing and the JTAG programming specifications for the CPLD seems to be hard to find. I also thought about JED-to-SVF to make it easier.

I already have the JTAG interface running, but i dont know how i should load the data or instruction registers.

Does anyone know if there is a common standard for JTAG programming a flash? More specifically a Macronix 29LV160BBTC.

Thanks for the help so far...

 

[Guest]

jedec to svf

A tool called 'naxjp' _used_ to be available with source code. I've never used it, but it seems to support a few CPLDs and FPGAs. Unfortunately, the author doesn't seem to publish the source code now (at least I haven't seen it lately).

JED->SVF might be the easiest approach.

If you get more information on this topic, please post here. I'm also interested in parsing JED files and developing my own software to program CPLDs (CoolRunner 2 for now).

 

[mavo]

.jed format

I found the CPLD programming specifications here: **broken link removed**

However they do not mention anything about JTAG. Does JTAG simply control the programming pins?

Added after 1 hours 51 minutes:

Here is some Java source for JTAG programming Xilinx CPLDs https://jcp.org/aboutJava/communityprocess/contrib/xilinx/index.html

 

[mavo]

jed to svf converter

Hi,

I located naxjp (naxjp-0.7.9-1) which includes sourcecode for the CPLD im interested in, and it seems it is able to load a .JED file.

I have not tried it yet, but i think i can use this to achieve my goal.