1. Chip size. You need to know what kinds of package will be used. ! T; V! I( N6 |: ~, F2. Pad location. You need to confirm with supplier about the bond wire bonding. + H6 N$ e; M1 o) B+ w( A3. ESD and latchup consideration. 2 B1 y4 s% k+ }5 Y3 ]1 B
4. Any noisy circuit inside the circuit. If yes, you may need to isolate those noisy circuits with double guard ring or individual ground and power path. ( D2 z! a$ g# q' Q |- I5. The current consumption on the whole circuit. It will affect the metal width of each building block and the whole circuit. . M& m) b5 L9 X" V6. Make sure there is no softcon connection. 5 H) M. N$ P6 E2 P7 C% \- t2 A4 i7. How many metal layers could be used ?) r+ k8 ^* V& n1 I- P8 m T1 Q
8. Metal Density consideration.