73M2901CE Data Sheet
DS_2901CE_031
3.4 External Interrupt Pins
Pin Name
RING
Pin Number
Type
Description
30
28
I
I
External interrupt – Line interface ring detection circuitry input
DTR
External interrupt – DTE DTR signal input
3.5 Oscillator Pins
Pin Name
OSCIN
Pin Number
Type
Description
19
18
I
Crystal input for internal oscillator, also input for external source
Crystal oscillator output
OSCOUT
O
8
Rev. 3.3