1 votes 1 votes Based on Input output Shift register is 4 types: 1: SISO 2: SIPO 3: PISO 4: PIPO what is the drawback of various types mentioned above??? my doubt is why we use each of them?(means if why we use parallel output if we have serial input already??) Hira Thakur asked Aug 4, 2017 Hira Thakur 199 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.