We have a CCA design which is 8 years old using the ADV7171 encoder which is all of a sudden showing problems during I2C configuration at hot temperatures. The problem seems to happen during configuration of the subcarrier frequency registers. The I2C message contains the 4 configuration bytes and they are being written in the correct order per the device spec. The message timing is good as per the I2C and ADV7171 spec. the SCA clock rate is 100Khz. The device does not acknowledge after the first byte is sent. I get good ack after the slave address and sub address. I also get good ack on other messages sent prior to the subcarrier message. This seems to happen when our unit is under test at temperatures around 55C. Has there been a recent update to this devices's silicon recently that can explain this sudden failure of these parts after 8 years of successfull operation? has anybody experienced Issues with I2C with these devices?
Lockheed martin Orlando Fla.