The global file contains global signal names for power (Vdd), ground (GND), and the chip reset signal (Reset). It also associates the sigtype attribute with these signals so that tools can associate these signals with the appropriate type. Include this file using

import globals;


pint SIG_POWER = 0,
     SIG_GROUND = 1,
     SIG_RESET = 2;
bool Vdd, GND, Reset;
Vdd @ [sigtype = SIG_POWER];
GND @ [sigtype = SIG_GROUND];
Reset @ [sigtype = SIG_RESET];