What's needed to Jtag in a chain?

[wyeshen]

hi. can I use one parallel port only to JTAG few mobile phones at once? I couldn't find the JTAG protocol online. Need some guidelines pls. Thanx.

 

[ntfreak]

Re: Jtag

Not possible as the devices will need to be on a jtag chain, eg. TDI - TDO - TDI - TDO etc.

Regards
NTFreak

 

[wyeshen]

Re: Jtag

Hi. you mean i can jtag in serial form? what do i need to change in my jtag programming? Thanx.

 

[tom_hanks]

Re: Jtag

JTAG....

can I use one parallel port only to JTAG few mobile phones at once? I couldn't find the JTAG protocol online.
for protocol..u need to know the type of chip...then u can use the bit file of the chip...to know the internal addresses...and then u can program them..


you mean i can jtag in serial form? what do i need to change in my jtag programming

chip's bit file..

 

[ntfreak]

Re: Jtag

To jtag in a chain you will need to connect the TDO to the next phone TDI and so on.
The other jtag pins can be connected in parallel.

Your software must be capable of putting the other devices in bypass mode while you progran the first phone, then the next phone and so on.

You will not be able to program all the phones at once.

Regards
NTFreak.