System and methods for communication over multifunction pins

A system comprising:

• a primary device to drive a clock bus and a data bus and to couple to a control bus;
• a plurality of secondary devices comprising:
• a clock input port to couple to the clock bus;
• a bidirectional data port to couple to the data bus;
• an address port to couple to the control bus;
• an address decoder circuit coupled to the clock input port, the bidirectional data port and the address port, the address decoder circuit to receive a clock signal from the clock input port and to receive a data signal from the bidirectional data port, and to decode the clock signal and the data signal to generate a decoded address field and the address decoder circuit to store the value of the address port in a non-transitory storage location and to compare at least one bit of the decoded address field to the stored value of the address port, and
• an internal control circuit to output a control signal to a pull-down circuit based on a predetermined condition, the pull-down circuit to selectively couple the address port to a ground node based on the value of the control signal.

A method comprising:

• receiving a data transmission from a primary device at a secondary device,
• storing the value of an address port to a stored address location in a non-transitory storage device,
• decoding the data transmission to generate a decoded address field,
• comparing at least one bit of the decoded address field with the stored address port value, and
• pulling down the voltage of the address port, based on a predetermined condition of the secondary device, to signal a status condition to the primary device.