The MC74LV594A is an 8bit shift register designed for 2 V to 6.0 V VCC operation. The device contain an 8bit serial in, parallel out shift register that feeds an 8bit D type storage register. The shift register (SRCLK) and storage register (RCLK) clocks are positive edge triggered. If the clocks are tied together, the shift register always is one clock pulse ahead of the storage register.