The PCF8584 is an integrated circuit designed in CMOS technology which serves as an interface between most standard parallel-bus microcontrollers/microprocessors and the serial I²C-bus. The PCF8584 provides both controller and target functions.
Communication with the I²C-bus is carried out on a byte-wise basis using interrupt or polled handshake. It controls all the I²C-bus specific sequences, protocol, arbitration and timing. The PCF8584 allows parallel-bus systems to communicate bidirectionally with the I²C-bus.