High-Performance Silicon-Gate CMOS The MC74HC589A is similar in function to the HC597, which is not a 3-state device. The device inputs are compatible with standard CMOS outputs, with pullup resistors, they are compatible with LSTTL outputs. This device consists of an 8-bit storage latch which feeds parallel data to an 8-bit shift register. Data can also be loaded serially (see Function Table). The shift register output, QH, is a three-state output, allowing this device to be used in bus-oriented systems. The HC589A directly interfaces with the Motorola SPI serial data port on CMOS MPUs and MCUs.