Universal JTAG User Manual (Parallel)

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Revision as of 21:57, 29 November 2009 by Admin (talk | contribs) (Unbuffered mode)
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10 PCS, 10cm x 10cm, 2 layers prototype for $38.80 shipped!

universal.jtag.135_2.jpgDG-JTAG-S03_small_1.jpgDG-JTAG-S02_small.jpgDG-JTAG-S04_small.jpgDB-BJTAG-04_small.jpgDG-JTAG-S05_small.jpgDG-BJTAG-03_small.jpg

Buy various JTAG cables for your Satellite Receiver, Cable Modem, Wireless Router, Standard Wiggler from http://www.easymg.com and http://www.diygadget.com

Why you need an universal JTAG adapter?

There are many different JTAG cables available in the market, often they are not compatible to each other. The problem was cause by the software. JTAG standard only defines a few hardware pinouts. However there is no standard definition on the PC side, e.g. which DB25 pin is for TDI? This is really depending on the software, some JTAG softwares may assume TDI is connected to pin 2 of DB25, but others may assume it is on pin 3. Even for the JTAG connector side, there are many different pinouts, 20 pin JTAG, 14 PIN, 12 PIN, 10 PIN etc... in a nutshell, you need a JTAG cable/adapter is flexible enough to allow you configure it for different softwares/programmers so you only need to invest on one JTAG adapter.


What is our universal JTAG adapter?

Our parallel universal JTAG adapter allows you to easily configure it to be a buffered or unbuffered JTAG. With provided flexible jumper wire you can move the pin configuration easily to suit different programmers.


Board layout

Universal JTAG in 3D

Universal JTAG layout


Buffered or unbuffered

The product comes with 6 x 50cm color coded flexible cable and 6 x 10cm color coded flexible cable.

If you want to use the adapter in unbuffered mode, you only use the 6 x 50cm flexible cables. Do not connect USB cable to your PC in this case.

If you want to use the adapter in buffered mode, you need all the cables plus you need to connect the adapter to your PC's USB port via a USB A to Mini USB B cable. Once the USB cable is connected, the PWR LED will light.


Configure it to use with TJTAG for wireless routers

In the following example, I am using Linksys WRTG54 wireless router as one example.


Linksys Series Routers JTAG Pinout
DB25 Router Function
2 3 TDI
3 9 TCK
4 7 TMS
5 1 TRST (Not Connected)
13 5 TDO
18-25 2,4,6,8,10 GND

Since TRST is not used, you only need 5 flexible cables.

Unbuffered mode

You just need 5x50cm flexible cable connected in such way:

Insert one end of the red flexible cable to D2, and the other end to your router's TDI, in this case is PIN 3.
Insert one end of the yellow flexible cable to D3, and the other end to your router's TCK, in this case is PIN 9.
Insert one end of the green flexible cable to D4, and the other end to your router's TMS, in this case is PIN 7.
Insert one end of the blue flexible cable to D13, and the other end to your router's TDO, in this case is PIN 5.
Insert one end of the black flexible cable to GND, and the other end to your router's GND, in this case is 2, 4, 6, 8 or 10.
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universal.jtag.135_2.jpgDG-JTAG-S03_small_1.jpgDG-JTAG-S02_small.jpgDG-JTAG-S04_small.jpgDB-BJTAG-04_small.jpgDG-JTAG-S05_small.jpgDG-BJTAG-03_small.jpg

Buy various JTAG cables for your Satellite Receiver, Cable Modem, Wireless Router, Standard Wiggler from http://www.easymg.com and http://www.diygadget.com


10 PCS, 10cm x 10cm, 2 layers prototype for $38.80 shipped!