| Author |
Message |
Mila
Joined: 07 May 2008
Posts: 2
|
 07 May 2008 15:58 direction of JTAG signal TDI and TDO at PMC interface |
|
|
|
Hallo professionals!
You have two boards: one is PMC mezzanine board and this board is placed at second (carrier board). You want use JTAG interface between this two boards.
Question is:
Is signal TDI input or output at carrier board?
At PCI and PMC standards I didn`t find explicit description of direction this signals.
Thank you very much for your help.
|
|
| Back to top |
|
 |
FvM
Joined: 22 Jan 2008
Posts: 2487
Helped: 409
Location: Bochum, Germany
|
| 07 May 2008 20:50 Re: direction of JTAG signal TDI and TDO at PMC interface |
|
|
|
| I can only imagine that PMC board JTAG interface is controlled from an external system (through the carrier board). Then the PMC board would have TDI (and also TCK and TMS) as input and TDO as output.
|
|
| Back to top |
|
|
ilikebbs
Joined: 30 Nov 2002
Posts: 83
Helped: 2
|
| 09 May 2008 4:46 direction of JTAG signal TDI and TDO at PMC interface |
|
|
|
| TDI is input in any condition.
|
|
| Back to top |
|
|
Mila
Joined: 07 May 2008
Posts: 2
|
| 19 May 2008 14:15 Re: direction of JTAG signal TDI and TDO at PMC interface |
|
|
|
Thank you,
I have the same idea as FvM, but I need exact description at some standard and I can΄t find this.
|
|
| Back to top |
|
|
sparso
Joined: 30 Dec 2006
Posts: 61
Helped: 1
|
| 06 Jun 2008 7:48 direction of JTAG signal TDI and TDO at PMC interface |
|
|
|
| Can any one explain the JTAG timing or post some material with the timing explanation?
|
|
| Back to top |
|
|
synq
Joined: 21 May 2001
Posts: 65
|
| 16 Jun 2008 13:48 Re: direction of JTAG signal TDI and TDO at PMC interface |
|
|
|
be more specific on Jtag timing are u trying to run an external JTAG chain ?
are you trying to initiate a JTAG scan internally?
first one need a esternal JTAg controller in which you can set appropriate frrequency in the range 100Hz to all the way up to 2M provide you interconnect system has got some good noise imunity to scan clocks...
and the joke is in a lab don't dream anything better than 10Khz ..hahaha cruel isn't it?
|
|
| Back to top |
|
|
stanislavb
Joined: 08 Jun 2008
Posts: 18
|
| 28 Jun 2008 10:40 Re: direction of JTAG signal TDI and TDO at PMC interface |
|
|
|
Attached JTAG timing example:
TCK Fftck Frequency 10MHz
TCK Ttckl Time low 50ns
TCK Ttckh Time high 50ns
TDI, TMS Ttsu Setup to TCK 40ns
TDI, TMS Tth Hold from TCK 40ns
TDO Ttval Valid from TCK 30ns
TDO Ttz Hi-Z from TCK 5ns 40ns
Enjoy!
|
|
| Back to top |
|
|
