About DS92LX1621 : PCLK setting

Hi Nao,

The DS92LX1621 and other Channel Link III devices require an external PCLK that is synchronized with the incoming high speed data to the serializer in order to work correctly. You will not be able to operate the serializer-to-deserializer communication correctly with only the internal oscillator.

When enabled, the internal oscillator serves primarily two functions:

1. The internal oscillator can be used as a clock source for BIST functionality, where the serializer ignores the parallel input data and sends a pre-determined BIST pattern from serializer to deserializer.

2. The internal oscillator is also used as a clock reference in the absence of the external PCLK in order to maintain back-channel communication and keep the I2C lines alive. For example, the internal oscillator could be used in a situation where a camera sensor on the serializer side is not active, yet you want to communicate I2C data back-channel, originating from the deserializer side.

Thanks,

Michael