4-bit register circuit diagram
Registers in Digital Electronics:
A register is a group of flip-flops with each flip-flop capable of storing one bit of information. An n-bit register has a group of n flip-flops and is capable of storing any binary information of n bits. In addition to the flip-flops, a register may have combinational gates that perform certain data-processing tasks. In its broadest definition, a register consists of a group of flip-flops and gates that affect their transition. The flip-flops hold the binary information and the gates control when and how new information is transferred into the register.
Various types of registers are available commercially. The simplest register is one that consists only of flip-flops, with no external gates. The 4-bit register circuit diagram shows that such a register is constructed with four D flip-flops.
The common clock input triggers all flip-flops on the rising edge of each pulse, and the binary data available at the four inputs are transferred into the 4-bit register. The four outputs can be sampled at any time to obtain the binary information stored in the register. The clear input goes to a special terminal in each flip-flop. When this input goes to 0, all flip-flops are reset asynchronously. The clear input is useful for clearing the register to all O’s before its clocked operation. The clear input must be maintained at logic 1 during normal clocked operation.