What are clock gating checks?

A clock gating check occurs when a gating signal can control the path of a clock signal at a logic cell. An example is shown in Figure 1. The pin of logic cell connected to clock is called clock pin and pin where gating signal is connected to is gating pin.

Why are clock gating checks required?

clock gating hold check is used to ensure that the EN is stable while the clock is active. A clock gating hold violation causes a glitch at the trailing edge of the clock pulse. In case1 above, EN is changing when the Clk signal is low. There is no possibility of a glitch in this case.

What is clock gating how it is implemented?

1 HOW TO IMPLEMENT CLOCK GATING When there is no activity at a register “data” input, there is no need to clock the register and hence the “clock” can be gated to switch it off. If the clock feeds a bank of registers, an “enable” signal can be used to gate the clock, which is called the “clock gating enable”.

What is clock gating path in VLSI?

Clock gating is a popular technique used in many synchronous circuits for reducing dynamic power dissipation, by removing the clock signal when the circuit is not in use. Clock gating saves power by pruning the clock tree, at the cost of adding more logic to a circuit.

What is power gating and clock gating?

Power vs Clock Gating While clock gating focuses on the dynamic power of the circuit by reducing the switching frequency, the power gating focuses on the static/leakage power of the circuit by reducing the flow of current through the circuit. The goal in power gating is to switch off the entire circuit when not in use.

Why clock gating checks are needed explain clock gating checks for a multiplexer?

With the increasing complexity of design in today’s fast changing world, the thrust on power saving has increased manifold. Consequently, gating the most toggling signal on the SoC i.e. the clock has become the norm now rather than an exception.

What is false path in VLSI?

A false path, as its name denotes is a timing path not required to meet its timing constraints for the design to function properly. In general all timing paths those are launched by a valid startpoint and captured by a valid endpoint impose setup and hold constraints.

What is difference between clock gating and power gating?

What is gating circuit?

An electronic circuit that consists of elements, which may be transistors, diodes, or resistors, combined in such a manner that they perform a logic operation. Gate circuits are the most basic building blocks of a digital system.

How do you stop glitches in clock gating?

Since the enable signal can change any time, which may not be synchronous with the clock signal, it can cause a glitch in the gated clock. To avoid this situation, a latch is added in front of the logic gate in order to synchronize the enable signal with the clock edge.

What is dynamic clock gating?

When you enable the dynamic high-level clock-gating feature, the cache controller stops its clock when it is idle. It does not stop the clock immediately when it is idle, but after it counts several clock cycles. See Power Control Register.