ADV7403 I2C read issue

I have developed an interface board to receive VGA data and output to RGB888

(24 bit RGB digital data).  I am having an issue where the I2C appears to be

programming the device correctly but read-back does not appear to work.  I have

worked on this for the last few days and thought that several things could be

wrong.  First, I connected TEST0 and TEST1 per the evaluation board design of

the 7403.  I have since disconnected these lines and there is no change.  I

have modified my I2C pullups and series resistors and this has not had an

impact.  When I write data, the device acknowledges on the 9th bit correctly. 

When I read data, I get the slave acknowledge up and until I begin to generate

clocks and perform a master acknowledge to the device.  The device appears to

not be giving any data back.  I also know that through the configurations I

have programmed, the pixel clock should be specific frequencies (65MHz, 75MHz,

etc.).  I have confirmed that these frequencies are in place so I am certain

that the device is operational.  I am just uncertain as to why it appears to be

block from the reads.  I am using a PIC 32MX795F512L with integrated I2C

peripheral to talk.  Any help would be greatly appreciated.

Parents
  • Dear Analog Device Experts

    I am Also facing same issue

    (i.e) WRITE TRANSATION is acknowledged by  the ADV7403 -- Working

            READ TRANSACTION is Not acknowledged by ADV7403 --Not Working

    After the Slave address 0x42 send by host , ADV7403 is pulling the data line at  9th clock position.

    But

    When the slave address 0x43 send by host, ADV7403 is not pulling the data line at 9th clock position.

    Wave form attached for both cases

    Pls suggest

    WRITE CYCLE -(ACK)

    i

    READ CYCLE --( NO ACK)

  • 0
    •  Analog Employees 
    •  Super User 
    on Jun 11, 2021 1:49 PM in reply to ramki

    Please start a new thread and include these images and reference this thread.  This thread was closed over 5 years ago.   We can better track this thread.  

    What is the host? Is it bit banged or peripheral driven?  What is the full sequence of byte attempted, both before and after?

    Initial guess would be a protocol problem with the host

Reply
  • 0
    •  Analog Employees 
    •  Super User 
    on Jun 11, 2021 1:49 PM in reply to ramki

    Please start a new thread and include these images and reference this thread.  This thread was closed over 5 years ago.   We can better track this thread.  

    What is the host? Is it bit banged or peripheral driven?  What is the full sequence of byte attempted, both before and after?

    Initial guess would be a protocol problem with the host

Children
No Data