Table of Contents
What are VLSI constraints?
Constraints can be any type – design related, cost related, resource related and market related. So Constraints are the instructions that the designer apply during various step in VLSI chip implementation, such as logic synthesis, clock tree synthesis, Place and Route, and Static Timing Analysis.
What are types of routing in VLSI?
Each stages of routing are described below.
- Global Routing. In global routing, the region to be routed are divided into sectors(tiles/rectangles) called global routing cells or gcells.
- Track Assignment.
- Detailed Routing.
- Detailed Routing.
- Search and Repair.
What is routing guide in VLSI?
A route guide specifies a rectan- gular region on a specific metal layer. A global routing solution for a net may contain several route guides on some or all of the metal layers. A detailed router needs to honor route guides, i.e., to route within route guides as much as possible.
What is timing constraint in VLSI?
The timing constraints is applied on input and output ports. The main target is to leave a budget in time for the signal outside the block. The designer should specify the time at which the inputs would be available on the block and should specify the time for which a signal travels outside the block for outputs.
What is Slew in VLSI?
Transition Delay. Transition delay or slew is defined as the time taken by signal to rise from 10 \%( 20\%) to the 90 \%( 80\%) of its maximum value. This is known as “rise time”.
What is the need of routing in VLSI?
The objective of routing is to minimize total wire length and number of vias and that each net meets its timing budget. The tools that perform routing are termed as routers. You typically provide them with a placed netlist along with list of timing critical nets.
What are SDC constraints?
SDC is a short form of “Synopsys Design Constraint”. SDC is a common format for constraining the design which is supported by almost all Synthesis, PnR and other tools. Generally, timing, power and area constraints of design are provided through the SDC file and this file has extension .
What are clock constraints?
Timing constraints is a vital attribute in real-time systems. Timing constraints decides the total correctness of the result sin real-time systems. The correctness of results in real-time system does not depends only on logical correctness but also the result should be obtained within the time constraint.
What is skew in VLSI?
Clock skew is a phenomenon in synchronous circuits in which the clock signal (sent from the clock circuit or source or clock definition point) arrives at different components at different times. due to. wire-interconnect length.