(ADV7182A)What are these scripts doing?

Hi 

We found these script at your evaluation board script.

42 52 CD ; SE_CVBS AFE IBIAS
42 9C 00 ; Reset Current Clamp Circuitry [step1]
42 9C FF ; Reset Current Clamp Circuitry [step2]
42 0E 00 ; Enter User Sub Map
42 13 00 ; Enable ADV7182A for 28_63636MHz crystal

What are these things doing?

Q1)
0x52 is hidden register.
Why we need these script?

Q2)
0x9C is read only.
Why we need to write this?

Q3)
I couldn't find information for these two.
42 0E 00 ; Enter User Sub Map 
42 13 00 ; Enable ADV7182A for 28_63636MHz crystal
What are these two doing?

Best regards

Kawa

Parents
  • +1
    •  Analog Employees 
    on Jan 13, 2021 2:45 PM

    Hi Kawa-San,

    Please find the below inline comments,

     Q1) 0x52 is hidden register.
            Why we need these script?

    These writes are normally determined during characterization of the part and we typically do not release any detail on them unfortunately.

    Q2) 0x9C is read only.
           Why we need to write this?

       The Reset Current Clamp Circuitry writes be performed each time the INSEL register is written to. This will speed up the lock time of the ADV7182.

    Q3) I couldn't find information for these two.
    42 0E 00 ; Enter User Sub Map 
    42 13 00 ; Enable ADV7182A for 28_63636MHz crystal
    What are these two doing?

        As per expert comment "ADV7182 datasheet states that register 0x13 is a read only register (status register 3). Actually two registers share the register address 0x13.

    When you read from register 0x13, you read back the Status Register 3 data ( this is read only) . When you write to register 0x13 you write to an internal control register. The internal control register is write only and contains the XTAL_TTL_SEL bit ".

    Please refer here (+) How Do I Use An External Oscillator to Clock the ADV7182 ? - Q&A - Video - EngineerZone (analog.com)

    Thanks,

    Poornima

Reply
  • +1
    •  Analog Employees 
    on Jan 13, 2021 2:45 PM

    Hi Kawa-San,

    Please find the below inline comments,

     Q1) 0x52 is hidden register.
            Why we need these script?

    These writes are normally determined during characterization of the part and we typically do not release any detail on them unfortunately.

    Q2) 0x9C is read only.
           Why we need to write this?

       The Reset Current Clamp Circuitry writes be performed each time the INSEL register is written to. This will speed up the lock time of the ADV7182.

    Q3) I couldn't find information for these two.
    42 0E 00 ; Enter User Sub Map 
    42 13 00 ; Enable ADV7182A for 28_63636MHz crystal
    What are these two doing?

        As per expert comment "ADV7182 datasheet states that register 0x13 is a read only register (status register 3). Actually two registers share the register address 0x13.

    When you read from register 0x13, you read back the Status Register 3 data ( this is read only) . When you write to register 0x13 you write to an internal control register. The internal control register is write only and contains the XTAL_TTL_SEL bit ".

    Please refer here (+) How Do I Use An External Oscillator to Clock the ADV7182 ? - Q&A - Video - EngineerZone (analog.com)

    Thanks,

    Poornima

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