Types of Synthesis
There are basically two types of synthesis:
1. Logical Synthesis
2. Physical Synthesis
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Logical Synthesis
To perform the logical synthesis, we need to have basic inputs like RTL, SDC, UPF and Timing lib. In this type of synthesis, we perform the logical level conversion to circuit level without any physical inputs.
Initially we receive the RTL from RTL design and verification team. Along with RTL, we receive the UPF from Power design team and Timing library from characterization team. At this point of time, we don’t have much information about the physical appearance of the design. So we go for first round of logical synthesis. From this, we get the logical gate level netlist from where we can start the floorplan and placement.
Synthesis Steps
Synthesis basically performs the following steps:
1. Translation
2. Logic Optimization
3. Gate level mapping
4. Final optimization
PROs –
- Requires very less inputs to start the synthesis.
- Runtime is very less.
- Gets early information about the circuit design and hierarchy.
CONs –
- No physical information present.
- No early legalized design to start the placement.
- Bad correlation between the placement.
- Bad timing correlation as no trial route information present.