def METHOD_NAME(self, port_num):
    # Check for invalid port_num
    if port_num < self.port_start or port_num > self.port_end:
        return False
    # Port offset starts with 0x4004
    port_offset = 16388 + ((port_num-1) * 16)
    status = self.pci_get_value(self.BASE_RES_PATH, port_offset)
    reg_value = int(status)
    # Absence of status throws error
    if (reg_value == ""):
        return False
    # Mask off 4th bit for presence
    mask = (1 << 4)
    # Mask off 1st bit for presence 33,34
    if (port_num > 32):
        mask =  (1 << 0)
    # ModPrsL is active low
    if reg_value & mask == 0:
        return True
    return False