Add area estimation, but yosys scripts need to be fine-tuned. Not yet accurate

Author: dpretet

syn/yosys/README.md

@@ -12,3 +12,26 @@ To run them:
 # To run AXI4-lite crossbar
 ./syn_asic.sh axicb_axi4lite.ys
 ```
+# cmos.lib
+
+The library is a generic, very minimalist, liberty file.
+
+AXI4 Crossbar:
+
+| Name     |     Count  |   NAND2 Count |
+| -------- | ---------- | ------------- |
+| DFF      |    10656   |  106560       |
+| DFFSR    |     2928   |  46848        |
+| NAND     |    67013   |  67013        |
+| NOR      |    23796   |  71388        |
+| NOT      |     9831   |  9831         |
+| Total    |   228448   |  301640       |
+
+The gate count is extracted from Yosys synthesis and the
+NAND2 is an estimation based on the next figures:
+
+- DFF: 10 NAND2
+- DFFSR: 16 NAND2
+- NOR: 3 NAND2
+- NOT: 1 NAND2
+- NAND: 1 NAND2