The 74HC595 consists of an 8 bit shift register and an 8 bit D type latch with three state parallel outputs. The shift register accepts serial data and provides a serial output. The shift register also provides parallel data to the 8 bit latch. The shift register and latch have independent clock inputs. This device also has an asynchronous reset for the shift register. The HC595 directly interfaces with the SPI serial data port on CMOS MPUs and MCUs.