DS90UB948-Q1: Remote EDID usage

Hello Chris,

The DS90UB949-Q1 can be configured to automatically accesses the Bidirectional Control Channel to search for an EDID EEPROM located at the downstream Deserializer’s local I2C bus. If so enabled, the Serializer automatically search for the EDID information at the default EDID I2C address 0xA0 (8-bit address). Once found, the Serializer copies the remote EDID information into its local EDID SRAM. The remote EDID device can be a standalone I2C EEPROM, or integrated into the digital display panel.

In this mode, to load external EDID from the EEPROM at the remote display, set the Serializer’s MODE_SEL0 = 1. For MODE_SEL1, REM_EDID_LOAD = 1 and EXT_CTL = 1 must be set as well.
Remote EDID Load is disabled by setting Register 0x54[5] = 1. Note: this is a strap bit, so the value is loaded from the MODE_SEL1 pin at power-up.

Note that, important for you as the Deserializer’s board designer is you need to know that once the Deserializer is powered-on, i.e. PDB is enabled, the Serilaizer will access the Deserializer’s local I2C bus within less than 1ms, looking for the address 0xA0 (8-bit address).
At this point the local I2C master must be made aware of this remote access to avoid any I2C collisions.
The other option to avoid collisions is to ensure that all I2C masters on the bus support multi-master arbitration, as mentioned in the data sheets.