DS90UB947-Q1: DS90UB947-Q1: Display flashing

  • Hi Ian,

    I will email it to you.

    - Fadi A.

  • Dear

    when i perform digital reset, will lost i2c communication to 947 chip. I guss it relate to I2C_VSEL. In my board, the strap of I2CSEL is 1.8V. After digital reset, the I2C_VSEL changed to 3.3V. So how to solve it ?

    -----------

    BR

  • Hi Ian,

    So after the 947 soft reset you're getting I2C Nacks and you're not able to communicate with the Serializer at all?

    Can you provide the I2C waveform of the I2C transaction/NACK? Do you have access to a Logic Analyzer to capture this behavior?

    Have you tried overriding the I2C_VSEL value back to 1.8V after the reset? 

      

    Regards,
    Fadi A.

  •  after the 947 soft reset i getting I2C Nacks and i not able to communicate with the Serializer at all

  • <?xml version="1.0" encoding="UTF-8"?>
    <settings>
        <global>
            <version>3.6.0</version>
            <devModel>8</devModel>
            <oscCursorEna/>
            <lgcMeasure/>
            <chnShowIndex>15,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14</chnShowIndex>
            <chnShowMultip/>
            <chnShowName0/>
            <chnShowName1/>
            <chnShowName2/>
            <chnShowName3/>
            <chnShowName4/>
            <chnShowName5/>
            <chnShowName6/>
            <chnShowName7/>
            <chnShowName8/>
            <chnShowName9/>
            <chnShowName10/>
            <chnShowName11/>
            <chnShowName12/>
            <chnShowName13/>
            <chnShowName14/>
            <chnShowName15/>
        </global>
        <devices>
            <LA5016>
                <trgPosition/>
                <chnTrig>3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0</chnTrig>
                <chnEnable>1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0</chnEnable>
                <smpMode>1</smpMode>
                <smpDepth>5000</smpDepth>
                <smpDepthIndex>4</smpDepthIndex>
                <smpFrequ>5000</smpFrequ>
                <smpFrequIndex>6</smpFrequIndex>
                <chnLevel>1.2V CMOS</chnLevel>
                <chnVth>0.60</chnVth>
            </LA5016>
        </devices>
        <analyzers>
            <item0>
                <fileName>I2C.dll</fileName>
                <parameters>I2CAnalyzer,1,0,0,0,0,</parameters>
                <format>2</format>
            </item0>
        </analyzers>
    </settings>
    kvdat@KL@KL��##D������������������������������������������
    ���(W.W5W;WBWIWPWSWTWVW]WdWkWqWxWW�W�W�W�W�W�W�����������������������������	����$�+�-�/�2��d�d�d�d�d�d�d�d�d�d�deeeee&e,e3e:eAeGeNeQeReUe��	��	��	��	��	��	��	��	��	��	�	�	�	�	�	#�	*�	1�	7�	>�	F�	L�	r#r*r1r8r>rErLrSrYr`rgrorur|r�r�r�r�r�r�r�r;�@�H�N�U�[�b�i�p�v�}��������������������5�5�5�5�5�5�5�5�5�5�5666
    6666%6,646:6�����������������������
    ����%�+�2�9�@�F�M�T��B�B�B�B�B�B�B�B�B�B�BCCCCC#C)C0C7C>CDCKCRCI�P�W�]�d�k�r�y����������������������������� P&P-P3P:P>P?PAPHPNPUP\PcPgPhPiPpPwP~P�P�P�P�P�P-2 .2 /2 42 ;2 A2 H2 O2 V2 ]2 d2 j2 q2 x2 2 �2 �2 �2 �2 �2 �2 �2 ��!��!��!��!Ÿ!̸!Ӹ!ٸ!�!�!�!�!�!�!�!��!��!�!	�!�!�!�!$�!+�!t?#z?#�?#�?#�?#�?#�?#�?#�?#�?#�?#�?#�?#�?#�?#�?#�?#�?#�?#�?#��$��$��$��$��$��$�$
    �$�$�$!�$(�$/�$5�$<�$C�$J�$P�$W�$Z�$[�$^�$RL&XL&_L&fL&mL&sL&zL&�L&�L&�L&�L&�L&�L&�L&�L&�L&�L&�L&�L&�L& �'&�'-�'4�';�'<�'=�'A�'H�'I�'J�'O�'V�'[�'\�']�'c�'j�'r�'x�'�'��'��'��'��'��''0-040:0A0H0O0U0\0_0`0c0j0p0w0x0y0~0�0�0�0�0�0�0�0�0�1�1�1�1 �1'�1.�14�1;�1B�1I�1O�1V�1Y�1Z�1]�1d�1j�1q�1x�1�1��1�3�3�3�3�3�3�3�3�3�3�3�3�3�3�3�3�33333 3^�4_�4`�4e�4l�4r�4y�4��4��4��4��4��4��4��4��4��4��4Ĩ4˨4Ѩ4ب4ߨ4X/6^/6e/6k/6r/6s/6t/6y/6�/6�/6�/6�/6�/6�/6�/6�/6�/6�/6�/6�/6�/6�/6�7�7�7�7�7��7��7�7�7�7�7�7&�7,�73�76�77�7:�7A�7G�7N�7Q�7R�7U�7]�7b�77�?8�?;�?>�?E�?K�?S�?Y�?a�?g�?n�?t�?{�?��?��?��?��?��?��?��?��?��?[uAauAhuAouAvuA|uA�uA�uA�uA�uA�uA�uA�uA�uA�uA�uA�uA�uA�uA�uA!�B'�B.�B5�B<�BB�BI�BP�BW�B]�Bd�Bk�Br�Bx�B�B��B��B��B��B��B��D��D��D��D��D��D��D��D��D‚DɂD̂D͂DЂDׂD݂D�D�D�D��D��D�D�D�D�F�F�F�F�F�F�F�F�F�FF
    FFF F&F-F3F:FAFHFNFN�GT�G[�Gb�Gi�Gp�Gw�G}�G��G��G��G��G��G��G��G��G��G��GȐGɐGʐGΐG$L$L$L%$L,$L2$L9$L@$LH$LN$LU$L[$Lb$Li$Lp$Lv$L}$L�$L�$L�$L@KL##D����������
    ���$W'W(WEW`WnW|W�W�W�W���������!�/�6��d�dee)eDeReYe��	��	�	�	 �	;�	H�	O�	r;rVrdrqr�r�r�r7�X�s������������5�5�566)666=6����
    ��(�C�Q�X��B�BCC&CACOCVCF�h�������������P>PYPfPtP�P�P�P*2 L2 g2 t2 �2 �2 �2 �2 ��!ɸ!�!�!��!�!'�!.�!p?#�?#�?#�?#�?#�?#�?#�?#��$��$�$$�$2�$M�$[�$b�$NL&pL&�L&�L&�L&�L&�L&�L&�'>�'Y�'[�'\�'g�'t�'��'��'��'#0$0%0E0`0m0{0�0�0�0�1#�1>�1L�1Z�1u�1��1��1�3�3�3�3�3�3�333$3[�4}�4��4��4��4Ψ4ܨ4�4T/6u/6�/6�/6�/6�/6�/6�/6ߵ7�7�7)�77�7R�7_�7f�74�?:�?;�?V�?q�?~�?��?��?��?��?WuAyuA�uA�uA�uA�uA�uA�uA�B?�BZ�Bh�Bu�B��B��B��B��D��D͂DڂD�D�D�D�D�F�FFFFF"F>FKFRFK�Gl�G��G��G��G��GːGҐG
    $L/$LJ$LX$Le$L�$L�$L�$L@KL

    pls rename 抓947寄存器复位后无ACK.kvdat.txt to 抓947寄存器复位后无ACK.kvdat

  • Hi Ian,

    As stated in the 947 datasheet, it is most likely the issue because resetting 947 via digital reset also changes the I2C voltage level selection to 3.3V. If the bus is running at 1.8V it will no longer communicate so only PDB reset can be utilized in the system if that is the case.

    As far as the "DS90Ux947-Q1 Init Code Example Rev 1p1" I don't see a requirement in this Errata script for a soft reset of the 947. It appears the script is actually performing a soft reset on the 948 (the Deserializer) for AEQ optimization. So there is no requirement to soft reset the 947 from TI side. 

    In case you need to have the option of resetting the 947 still available to you for future use-case, etc. to resolve this mismatch between your 1.8V host and the 3.3V device, I recommend a hardware (Best Practice): Use an I2C Level Shifter (logic translator) to ensure the voltage levels remain consistent for both sides regardless of the chip's state. 

    Adding the level shifter will give you the flexibility to soft reset the Ser without running into issue in case you need to soft reset the Ser in the future for any other reason outside of this request as per TI's Errata code there is no requirement to soft reset the 947 at all. 

    Regards,
    Fadi A.