# What is clocking in VLSI?

## What is clocking in VLSI?

Definition of clock signal: We can define a clock signal as the one which synchronizes the state transitions by keeping all the registers/state elements in synchronization. In common terminology, a clock signal is a signal that is used to trigger sequential devices (flip-flops in general).

### Why do we use VLSI clocking?

The whole reason that we need clocks is that we want the output to depend on more than just the inputs, we want it to depend on previous outputs too. These previous outputs are the state bits of the FSM, and are the signals that cause lots of problems.

What are the advantage of two phase clock?

Two-phase clock Because the two phases are guaranteed non-overlapping, gated latches rather than edge-triggered flip-flops can be used to store state information so long as the inputs to latches on one phase only depend on outputs from latches on the other phase.

What is ideal clock in VLSI?

An “ideal” clock has no physical distribution tree, it just shows up magically on time at all the clock pins. It refers to the delay that is specified to exist between the source of the clock signal and the flip-flop clock pin. This is a delay specified by the user – not a real, measured thing.

## What kind of clock is used for VLSI 6?

•The clock is a simple pulsating signal alternating between 0 and 1. •Digital systems use a number of clocking schemes: 1. Single-phase clocking with latches 2. Single-phase clocking with flip-flops 3. Two-phase clocking Clock period t CLK CAD for VLSI 6 Single-phase Clocking with Latches •The latch opens when the clock goes high.

### Why is clock synchronization important in a VLSI circuit?

•Clock synchronization is one of the most critical considerations in designing high-performance VLSI circuits. –Data transfer between functional elements is synchronized by the clock. –It is desirable to design a circuit with the fastest possible clock. •The clock signal is typically generated external to the chip.

What is internal logic of CLK tcycle CLK?

Tuncertainty Clk Tcycle Clk’ 9/27/18 3 DFF DFF Din Delay COMB Dout Delay CLK Internal logic & wire delay from input pin to register Input(s) CLK’ Internal logic & wire delay from register to output pin Output(s) Internal logic bound by F2F timing Clock Skew= CLK -CLK’