4000 series cmos logic family texas instruments cd4021be this texas instruments cd4021b 8 stage static shift register ic is available in a dil 16 package a part of the cmos 4000 range the shift register can operate in parallel or serial mode in parallel mode the state of the 8 jam inputs is loaded into the register on the positive transition of the clock signal in serial mode the state of the serial input line is transferred into the shift register on the positive clock transition output