I'm designing a board using the ADV7623 chip to be used as a 4 port switch with ethernet controlled CEC capabilities and have a couple of questions regarding the IC (and the evaluation board design).
- The evaluation board uses external I2C EEPROMs for EDID storage. What is the advantage of this as opposed to using the internal SRAM? Is it purely so the information can still be extracted when the ADV7623 is not powered on?
- What is the purpose of the IO expander chip U39 on the evaluation board? Seems to be a static 16 bit value accessible for I2C as some sort of addressing.
- Is resistor R157 (crystal shunt) required for starting the crystal or does it serve another purpose?
- The datasheet recommends the ADV7623 is on the same side of the board as the HDMI connectors. Are there any major implications for having connectors on both sides of the board as long as via impedance is taken into account?
Thanks for your time.