Table of Contents
What is the use of latch in ICG cell?
A latch-AND ICG cell consists of an active low latch followed by an AND gate, and is primarily used to drive positive edge triggered flip-flops. The latch is added to eliminate any hazard in the En signal which otherwise could propagate to the GClk.
Why latches are level triggered?
Level triggered flip-flop are generally called as latches. It gets triggered at the levels of the clock pulse. This has a disadvantage because it generates race around condition, the condition in which the output races(changes rapidly from 0 to 1 and 1 to 0 during the entire time period, say T/2).
Why latch is level triggered and flip-flop is edge triggered?
The difference between a latch and a flip-flop is that a latch is level-triggered (outputs can change as soon as the inputs changes) and Flip-Flop is edge-triggered (only changes state when a control signal goes from high to low or low to high). Latches are something in your design that always needs attention.
What is ICG cell?
Clock gating is a common technique for reducing clock power by shutting off the clock to modules by a clock enable signal. To avoid this, a special kind of clock gating cells are used, that synchronizes the EN with a clock edge. These are call integrated clock gating cells or ICG.
How is latch different from flip flop?
The major difference between flip-flop and latch is that the flip-flop is an edge-triggered type of memory circuit while the latch is a level-triggered type. On the other hand, the latch only changes its state whenever the control signal goes from low to high and high to low.
How is latch different from flip-flop?
What is the difference between flip-flop and latch?
Flip-flop is a bistable device i.e., it has two stable states that are represented as 0 and 1. Latch is also a bistable device whose states are also represented as 0 and 1. It checks the inputs but changes the output only at times defined by the clock signal or any other control signal.
What is an integrated clock gating cell (ICG)?
To avoid this, a special kind of clock gating cells are used, that synchronizes the EN with a clock edge. These are call integrated clock gating cells or ICG. There are two commonly used ICG cell types. The following design uses a negative edge triggered latch to synchronize the EN signal to the CLK.
What are the commonly used ICG cell types?
There are two commonly used ICG cell types. The following design uses a negative edge triggered latch to synchronize the EN signal to the CLK. The GCLK is available only when the latch o/p is high. GCLK is held low when EN is low. The following design uses a positive edge triggered latch.
Is a flip-flop an edge or level triggered device?
It is a edge triggered device. It is a level triggered device. Gates like NOR, NOT, AND, NAND are building blocks of flip flops. These are also made up of gates. They are classified into asynchronous or synchronous flipflops.