I checked datasheet and it says that 
TRST has INTERNAL  pull DOWN resistor
TMS  has INTERNAL  pull UP  resistor
TCK  has INTERNAL  pull UP  resistor
TDI  has INTERNAL  pull UP  resistor

and TDO requires EXTERNAL pull UP.
But when I checked the design of that device(using the processor)  ,  an 
external  PULL UP  
seems to be already there for TDO.

Do you mean that adding resistors to ALL JTAG pins should be pull UP 
resistors?( 
Eventhough datasheet says for TRST  that it uses internal pull DOWN resitor?
ANd do you think 10 k resitor is not TOO high?

And have you ever come across a CPU that had  JTAG disabled form the 
manufaturer ? Or 
are they  rumours only that a manufacturer disables JTAG, (eventhough datasheet 
says 
there IS JTAG evailable)?
Thanks for the reply



 

> > I read  about that and now I have a device that
> > reports all zeros
> > like this
> 
> Try to add external pull-up resistors (10K ohms) up to VCC on ALL of
> the JTAG pins.
> 
> Stian Skjelstad
> 



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