ACL for 1720 with WIC 1ADSL

I have sucessfully set up my 1720 with a WIC 1ADSL and and now wish to implement an access list. My question is what interface do I implement the access list and why that interface? Is it the interface ATM0 or Interface Dialer1 ?

interface ATM0
 no ip address
 no atm ilmi-keepalive
 dsl operating-mode auto
 pvc 0/38
  encapsulation aal5mux ppp dialer
  dialer pool-member 1
 !
!
interface FastEthernet0
 ip address xxx.xxx.xxx.xxx xxx.xxx.xxx.xxx
 ip nat inside
 speed auto
!
interface Serial0
 no ip address
 shutdown
!
interface Dialer1
 ip address negotiated
 ip access-group 101 in
 ip mtu 1452
 ip nat outside
 encapsulation ppp
 dialer pool 1
 dialer-group 1
 ppp authentication chap callin
 ppp chap hostname xxx
 ppp chap password 0 xxx
!
ip nat inside source list 1 interface Dialer1 overload
ip nat inside source static xxx.xxx.xxx.xxx xxx.xxx.xxx.xxx
ip classless
ip route profile
ip route 0.0.0.0 0.0.0.0 Dialer1
no ip http server
!
access-list 1 permit xxx.xxx.xxx.xxx xxx.xxx.xxx.xxx
dialer-list 1 protocol ip permit

thanks