71. What are the inputs for CTS?
- Placement netlist (.v)
- Sdc
- Placement def
- Lef
- Lib
- Captables
- Spec
72. What are the inputs for routing?
- cts netlist (.v)
- cts def
- sdc
- lef
- lib
73. After routing what you will check?
- timing (drv’s , setup and hold)
- drc’s ( design rule checks )
- core utilization
- cell legality
- congestion
74. what is skew? and what are the different types of skew?
Types of skew:
1. Positive skew
2.negative skew.
Positive skew improves setup and degrades hold
Negative skew improves hold and degrades setup.
75. What challenges you faced in your project?
a) Congestion, timing and drc’s.
76. How many iterations you did in floorplan?
a) I did upto 20 iterations.
77. What are Endcap cells? Why we use it?
a) Endcap cells are the physical only cells, which are placed at the boundary of the chip to
avoid cell damage during fabrication and to provide nwell continuity to the std cells at the
end of the rows.
78. what is the command for partial blockage?
a) CreatePlacementBlockage –type partial –density 65 –box {x1 y1 x2 y2}
79. why we use halo?
a) Halo is one type of blockage; it placed around the macros to avoid base drc violations.
80. what is skew, useful skew and global skew?
a) Skew is the difference between capture latency and launch latency.
Useful skew is the technique that is improving setup without impacting the hold
violation.
Global skew is difference between max latency and min latency.