DNS-320L Jtag

[Elektronix]

Hi

Can anyone assign name of jtag points in the marked area ?

Thx

 

[sfx2000]

What you have highlighted is not a jtag...

You probably don't need JTAG, use the serial port - it's next to the magnetics over by the USB port...

[ - - -]

If you can get into Marvell uboot, you can reflash the device from there...

Good info here...

https://github.com/martignlo/DNS-320L

good luck!

 

[Elektronix]

I know where the serial port is, but i wanted to test connection through jtag and some of the point i've already determined, but i can not read id mcu. Nowhere can i find a description of jtag output for this pcb type. This mcu have on 100% jtag port , because other pcb with the same mcu have it and surely it is in a place whom i have indicated.

 

[sfx2000]

Found a better pic of the 320L board here... so those pads might be JTAG after all...

http://developers-club.com/posts/244921/

I would also look at this -- http://dns323.kood.org/hardware:jtag

(note that sometimes you'll need to enable the port if it isn't already, read the notes there for other items)

Index off VCC, and count over... VCC and GND's are easy to find, then it's reverse engineering from there - in my experience, most Marvell boards are fairly consistent once you index where VCC is.

 

[sfx2000]

I know where the serial port is, but i wanted to test connection through jtag and some of the point i've already determined, but i can not read id mcu. Nowhere can i find a description of jtag output for this pcb type. This mcu have on 100% jtag port , because other pcb with the same mcu have it and surely it is in a place whom i have indicated.

What, exactly, are you trying to do?

If you're trying to recover from a corrupt NAND, there are ways to do this w/o JTAG by configuring uBoot on a USB key to load into RAM - there you can do pretty much what is need (erase NAND, reload uBoot, and get things back up and running).

couple of more items of interest...

https://groups.google.com/forum/#!topic/alt-f/BdIM55T7ths

https://groups.google.com/forum/#!msg/alt-f/uhxqZ0N-H28/XNzot2oKEQAJ