Part Number: DP83848K
I need to read the register "BMSR" of DP83848K, and I only read back "FFFF" using boundary scan tools, as shown below:
PHY and REG Address: 00000201h - 00000000.00000000.00000010.00000001
Read Data: 0000FFFFh - 00000000.00000000.11111111.11111111
Do I need to add any additional commands?
Have you confirmed any other registers are working properly? Are you using the correct PHY ADDRESS?
We are glad that we were able to resolve this issue, and will now proceed to close this thread.
If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.
In reply to Cecilia Reyes:
Thanks very much for your assistance, and we are using the proper address. We have 2 devices at this address:
Address 0201h and 0221h
I wonder if this device requires a double reading as indicated on this link for a different part? https://e2e.ti.com/support/interface/f/138/t/550756?Problems-reading-DP83822-register-0x0001-Basic-Mode-Status-Register
There is no issue with the DP83822.The reason why you are having issue is because register 0x01 always requires two reads.This bit in the register is a LL (latch-low). Thus two reads are required to get the correct real-time status.Typically double reads are inate to the firmware. Please ensure your firmware does a double read.Kind regards, Ross"
Thanks very much,
In reply to Frank Valenzuela:
That is correct. The DP83848 also requires a double read since it is latch low.
More details on this e2e thread: https://e2e.ti.com/support/interface/f/138/t/654758
Thanks for your info, but still having issues. I will be troubleshooting the hardware ckt and advise progress or issues later on.
Would you have access to an MSP launchpad or use our USB2MDIO tool? I am wondering if you'd be able to read and write to registers directly from MDIO/MDC pin to confirm it is not a PHY issue.
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.