610 V2 - E3000 jtag

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barryware
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Joined: 26 Jan 2008
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PostPosted: Mon Jul 05, 2010 18:00    Post subject: 610 V2 - E3000 jtag Reply with quote
Linksys has disabled the jtag port on the 610_V2~E3000

JB3 is the jtag port (10 pin), JB2 under the board is serial, JB1 is a 14 pin micro pad header. This is also jtag but goes to the radio chip and is operational.

The jtag for the processor has been disabled by leaving out smt resisters in the circuit. I traced the pins to the missing resisters.

Pin 1 ~ RC27
Pin 3 ~ RC28
Pin 5 ~ RC29
Pin 7 ~ RC30
Pin 9 ~ PC31

I don't know the value of the resisters. I can't get the value off of other hardware I have cuz the resister pads are blank but they are in circuit somewhere cuz the jtag works..

Think it would be safe to just bridge the resister pads (zero ohm)?

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Last edited by barryware on Fri Jul 09, 2010 22:25; edited 1 time in total
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redhawk0
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PostPosted: Fri Jul 09, 2010 21:22    Post subject: Re: 610 V2 - E3000 jtag Reply with quote
barryware wrote:
Linksys has disabled the jtag port on the 610_V2~E3000

JB3 is the jtag port (10 pin), JB2 under the board is serial, JB1 is a 14 pin micro pad header. This is also jtag but goes to the radio chip and is operational.

The jtag for the processor has been disabled by leaving out smt resisters in the circuit. I traced the pins to the missing resisters.

Pin 1 ~ RC27
Pin 3 ~ RC28
Pin 5 ~ RC29
Pin 7 ~ RC30
Pin 9 ~ PC31

I don't know the value of the resisters. I can't get the value off of other hardware I have cuz the resister pads are blank but they are in circuit somewhere cuz the jtag works..

Think it would be safe to just bridge the resister pads (zero ohm)?

BTW.. Still need a virgin unmodified E3000 CFE.


I wouldn't bridge it to 0 ohms....most JTAG pull up resistors are 4.7K

I'd start there.

redhawk

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Bird333
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Joined: 07 Jun 2006
Posts: 807

PostPosted: Sat Jul 17, 2010 13:08    Post subject: Reply with quote
Barryware, did you ever figure out the jtag pads on a 610 v1?
barryware
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Joined: 26 Jan 2008
Posts: 12833
Location: Behind The Reset Button

PostPosted: Sat Jul 17, 2010 13:17    Post subject: Reply with quote
Bird333 wrote:
Barryware, did you ever figure out the jtag pads on a 610 v1?


a V1 has operational jtag.. It is the V2 that has the jtag disabled.

btw.. I f$cked up the board on the v2 by lifting pads / traces trying to bridge the pads.. I may still be able to fix it but haven't been back to it since I screwed it up..

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bennyc
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Joined: 13 Feb 2011
Posts: 3
Location: Belgium

PostPosted: Thu Feb 24, 2011 14:24    Post subject: enable jtag Reply with quote
Hi, did anyone succeeded in making this jtag work? (have a dead e3000, no bootloader no serial)
resistors are so small (0402??) that soldering them by hand seems impossible.
But if they are just pull-ups, should mean the pcb tracks make it to the processor? so it should be possible to use the connector holes and solder pull-ups to the 3V3 line? (won't be pretty, but should work)
all feedback welcome... Smile

tnx, Benny.
barryware
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Joined: 26 Jan 2008
Posts: 12833
Location: Behind The Reset Button

PostPosted: Thu Feb 24, 2011 14:39    Post subject: Re: enable jtag Reply with quote
bennyc wrote:
Hi, did anyone succeeded in making this jtag work? (have a dead e3000, no bootloader no serial)
resistors are so small (0402??) that soldering them by hand seems impossible.
But if they are just pull-ups, should mean the pcb tracks make it to the processor? so it should be possible to use the connector holes and solder pull-ups to the 3V3 line? (won't be pretty, but should work)
all feedback welcome... Smile

tnx, Benny.


I made a post (maybe the convert your v2 to an e3000 thread) with pics.. I lifted the pads on two of these routers trying to bridge them. My plan was to bridge the pads, then make an adapter to interface with the jtag header with the 4.7k resisters in the adapter.

If you can successfully do it, jtag should work. The processor is the same as the rt-n16 and is supported by jtag as well as the parallel flash chip in the v2/e3000.

Both routers are in service. There is nothing wrong with the routers, just lifted a pad or two in the jtag circuit off the pcb.

Good luck..

EDIT.. Found the post with pics:

http://www.dd-wrt.com/phpBB2/viewtopic.php?t=75183&postdays=0&postorder=asc&start=164

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ink
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Joined: 08 Jun 2006
Posts: 123

PostPosted: Sat Feb 26, 2011 4:45    Post subject: Re: 610 V2 - E3000 jtag Reply with quote
barryware wrote:
Linksys has disabled the jtag port on the 610_V2~E3000

JB3 is the jtag port (10 pin), JB2 under the board is serial, JB1 is a 14 pin micro pad header. This is also jtag but goes to the radio chip and is operational.

The jtag for the processor has been disabled by leaving out smt resisters in the circuit. I traced the pins to the missing resisters.

Pin 1 ~ RC27
Pin 3 ~ RC28
Pin 5 ~ RC29
Pin 7 ~ RC30
Pin 9 ~ PC31

I don't know the value of the resisters. I can't get the value off of other hardware I have cuz the resister pads are blank but they are in circuit somewhere cuz the jtag works..

Think it would be safe to just bridge the resister pads (zero ohm)?



could you find out "BA2" pin? it's ddr2 Bank Address 2
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