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Ethernet controller i350, NHI350AM4 SLJ2Z Issue: Cannot access boundary scan register (BSR) in boundary scan mode.



IRCAPTURE register read passes.

IDCODE register read passes.

USERCODE register read passes.

 (from those successes, I conclude that TMS, TCK TDI, TDO, TRST are "working".)

Boundary scan register test, using the PREAMBLE opcode

 Our tools scan in a sentinel pattern, clock the BSR the length of the BSR, count the bits, clock the BSR for the number of bits in the sentinel pattern. The read bits are stored, but not checked for any value until the sentinel pattern is expected. However, if there _is_ a failure, all bits are checked for all ones or all zeros and the tool reports that to the user.

 The first access of the BSR returns all zeros.

 Our tools indicate a failure and only presents that result.

 My next step: I examined the bits in and out during the boundary scan register access. In this test, the BSR is actually tested twice. The first time, the read bits are all ones. However, the second test passes - the sentinel pattern is found, and in the expected bit location.

 I tried various experiments to get the first BSR read to be successful. No change in device behavior.



Is there something that needs to be done for a successful BSR read?

 An initialization?

 A timing accommodation? (Example, I worked with one device that required the TMS to be delayed 10ms.)

 Is the device sensitive to how the JTAG state machine is transitioned?

 Are two PREAMBLE opcodes required to successfully read the BSR?

Ultimately, for boundary scan testing, it is EXTEST that needs to work, but I cannot get to that phase of testing without first successfully using PREAMBLE and BSR read.


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3 Replies

Hello TYuen3,


Thank you for posting in Intel Ethernet Communities. 


Base on your inquiry, we have specific forum for these issues and I will be transferring this thread for faster response. 


Best regards,

Michael L.

Intel Customer Support Technicians

A Contingent Worker at Intel

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Hello, @TYuen3​:


Thank you for contacting Intel Embedded Community.


Could you please clarify that the units related to the cited condition are third-party design or yours?


Could you please give the part number, model, name of the manufacturer, where it is stated the information related to it if it is a third-party project?  


In case it is your design, could you please confirm that it has been reviewed by Intel? Could you please list the sources that you have used to develop it?


We are waiting for your reply.


Best regards,


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My error. These symptoms are on a different Intel device. I opened this question on the wrong device. This question can be deleted.

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