RTL Compiler之synthesis steps

1　　synthesis steps

1)　　Search Paths　　　　

　　　　rc:/> set_attribute 　lib_search_path　path /
　　　　rc:/> set_attribute 　script_search_path 　path / 
　　　　rc:/> set_attribute 　hdl_search_path　　path /

2)　　Target Technology Library

　　　　rc:/> set_attribute   library  lib_name.lib 

　　　- Target Library: Design Compiler uses the target library to build a circuit. During mapping, Design Compiler selects functionally correct gates from the target library. It also calculates the timing of the circuit, using the vendor-supplied timing data for these gates.

3)　　Loading the HDL Files

　　　- sequentially:　　 read_hdl   file1.v　　read_hdl   file2.v　　read_hdl   file3.v 

　　　- simultaneously:　read_hdl  { file1.v file2.v file3.v }　　

read_hdl [-v1995 | -v2001 | -sv
| -vhdl [-library library_name ]
| -netlist]
[-define macro=value ] ... file_list

4)　　Performing Elaboration

　　　　This is only required for top-level design. The elaborate command automatically elaborates the top-level design and all of its references.

5)　　Applying Constraints

　　　  - Operating conditions; clock waveforms; I/O timing

6)　　Applying Optimization Constraints

7)　　Performing Synthesis

　　　　rc:\> synthesize -to_mapped

8)　　Analyzing the Synthesis Results

　　　 - generate a detailed area report, use report area

　　　 - generate a detailed gate selection and area report, use report gates

　　　 - generate a detailed timing report, including the worst critical path of the current design, use report timing

9)　　Exporting the Design

　　　- gate-level netlist　　rc:/> write_hdl > design.v

　　　- design constraints 　rc:/> write_script > constraints.g 

　　　- constraints in SDC format　rc:/> write_sdc > constraints.sdc

10)　　Exiting RTL Compiler

　　　　quit or exit

2　　recommended flow

#general setup
#--------------
set_attributer lib_search_path ...
set_attribute hdl_search_path ..
#load the library
#------------------------------
set_attribute library library_name
#load and elaborate the design
#------------------------------
read_hdl design.v
elaborate
#specify timing and design constraints
#--------------------------------------
read_sdc  sdc_file
# add optimization constraints
#----------------------------
.....
#synthesize the design
#---------------------
synthesize -to_mapped
#analyze design
------------------
report area
report timing
report gates
#export design
#-------------
write_hdl > dessign.vm
write_sdc > constraints.sdc
write_script > constraints.g
# export design for EDI
#-----------------------
write_design [-basename  string ] [-gzip_files] [-tcf]
[-encounter] [-hierarchical] [ design ]

3　　working in the top-level(root) directory

　　Root is a special object that contains all other objects represented as a ‘tree’ underneath it.

　　The root object is always present in RTL Compiler and is represented by a “/”, as shown in above Figure.

　　Root attributes contain information about all loaded designs.