AnsweredAssumed Answered

ADV7611 i2c read issue

Question asked by daemon on Feb 20, 2013
Latest reply on Jan 9, 2015 by mattp



We are using 8 ADV7611 chips in each of our devices. ADV7611 accepting each value sent via I2C and

operates as described in the manual. So I2C write operations are fine. But when we try to read

from ADV7611 via I2C it doesn't answers to its I2C address!


This is example of successful writing to I2C address 0x98 (we got ACK):


And this is example of reading from the same address with no acknowledge bit from ADV7611:


Very strange!


Additional info:


- No matter which (valid) I2C address is used for read from ADV7611;

- I2C is running at 100 kHz;

- ADV7611 running from an external 27 MHz clock;

- Errornous I2C read behaviour is not dependant if read issued after a hard reset or after

successful ADV7611 settings (I2C writes), or in any other time. It also not dependant on

HDMI signal presense on ADV7611 input;

- This error is the same for all 8 ADV7611 chips in our device;

- Chip has such markings: "ADV7611-BSWZ-P #1140 2220602.1";

- Chip is working as expected after configuration, but now we need to poll ADV7611 registers;

- The same I2C write/read routine and similar hardware is working fine with SAA7114 analog video ADC;

- The backend for ADV7611 is Fujitsu MPEG-2 encoder (MB86391).


Very unexpected ADV7611 behaviour! Thanks in advance!