[Script] Add a template yosys script to enable DSP mapping

openfpga_flow/misc/ys_tmpl_yosys_vpr_bram_dsp_flow.ys

@@ -0,0 +1,102 @@
+# Yosys synthesis script for ${TOP_MODULE}
+
+#########################
+# Parse input files
+#########################
+# Read verilog files
+${READ_VERILOG_FILE}
+# Read technology library
+read_verilog -lib -specify ${YOSYS_CELL_SIM_VERILOG}
+
+#########################
+# Prepare for synthesis
+#########################
+# Identify top module from hierarchy
+hierarchy -check -top ${TOP_MODULE}
+# - Convert process blocks to AST
+proc
+# Flatten all the gates/primitives
+flatten
+# Identify tri-state buffers from 'z' signal in AST
+# with follow-up optimizations to clean up AST
+tribuf -logic
+opt_expr
+opt_clean
+# demote inout ports to input or output port
+# with follow-up optimizations to clean up AST
+deminout
+opt
+
+opt_expr
+opt_clean
+check
+opt
+wreduce -keepdc
+peepopt
+pmuxtree
+opt_clean
+
+########################
+# Map multipliers
+# Inspired from synth_xilinx.cc
+#########################
+techmap -map +/mul2dsp.v -map ${YOSYS_DSP_MAP_VERILOG} ${YOSYS_DSP_MAP_PARAMETERS}
+select a:mul2dsp
+setattr -unset mul2dsp
+opt_expr -fine
+wreduce
+select -clear
+chtype -set $mul t:$__soft_mul# Extract arithmetic functions
+
+#########################
+# Run coarse synthesis
+#########################
+# Run a tech map with default library
+techmap
+alumacc
+share
+opt
+fsm
+# Run a quick follow-up optimization to sweep out unused nets/signals
+opt -fast
+# Optimize any memory cells by merging share-able ports and collecting all the ports belonging to memorcy cells  
+memory -nomap
+opt_clean
+
+#########################
+# Map logics to BRAMs
+#########################
+memory_bram -rules ${YOSYS_BRAM_MAP_RULES}
+techmap -map ${YOSYS_BRAM_MAP_VERILOG}
+opt -fast -mux_undef -undriven -fine
+memory_map
+opt -undriven -fine
+
+#########################
+# Map flip-flops
+#########################
+techmap -map +/adff2dff.v
+opt_expr -mux_undef
+simplemap
+opt_expr
+opt_merge
+opt_rmdff
+opt_clean
+opt
+
+#########################
+# Map LUTs
+#########################
+abc -lut ${LUT_SIZE}
+
+#########################
+# Check and show statisitics
+#########################
+hierarchy -check
+stat
+
+#########################
+# Output netlists
+#########################
+opt_clean -purge
+write_blif ${OUTPUT_BLIF}