1. Chip size. You need to know what kinds of package will be used.0 h N7 X" H1 J
2. Pad location. You need to confirm with supplier about the bond wire bonding. 6 i' g' i7 W3 V6 @3. ESD and latchup consideration. 4 N) o0 u' ]& g ]1 Y1 A+ S4. 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. " D% ~' Y) M! ?. K2 b5. The current consumption on the whole circuit. It will affect the metal width of each building block and the whole circuit.6 B: V* O' B" p* e
6. Make sure there is no softcon connection.7 I7 q) N3 v3 z$ H, w$ }3 ~! L
7. How many metal layers could be used ? ! ` T* |! @/ U% I @& ^' F4 ~8. Metal Density consideration.