Registers in Computer Architecture

Register

·        A register is a group of flip-flops (FFs), each one of which shares a

·        common clock and is capable of storing one bit of information.

·        𝑛-bit register -> 𝑛 FFs

·        A counter is also a register that goes through a predetermined sequence of binary states.

·        Clear and Preset pins of the FFs can be used to initialize the FFs.

Register with Parallel Load

·        The transfer of new information to the register is called loading or updating the register.

·        If all the bits of the register are loaded simultaneously with a common clock pulse, then the loading is said to be in parallel.

·        The simultaneous changes in all the inputs is difficult to achieve.

·        To make the register content unchanged, there are two ways

o   Inputs must held constant

o   Clock must be inhibited from the circuit

·        Inserting gates into the clock path is not good.

Shift Register

A register capable of shifting the binary information held in each cell to its neighboring cell, in a selected direction, is called a shift register.

 

 

 

Universal Shift Register: