The CDCDB2000 has an SMBus interface that is active only when CKPWRGD_PD# = 1.The SMBus allows individual enable/disable of each output when the SMBus mode is selected using the SBEN pin.

When CKPWRGD_PD# = 0, the SMBus pins are placed in a Hi-Z state, but all register settings are retained. The SMBus register values are only retained while VDD_A remains inside of the recommended operating voltage.