Z02215
Single Chip Modem with Integrated Controller, Data Pump, and AFE
12
Operating Modes
The modem controller software features several different states of operation.
DIALING
HANDSHAKE
IDLE
RETRAIN
COMMAND
ON-LINE
Figure 4. Modem State Diagram
IDLE
When the modem is in the IDLE state it is not communicating with another
modem. The modem accepts AT commands from the terminal while IDLE.
DIALING
When the modem dials it performs the same tasks a person uses to dial a tele-
phone. The modem does not accept AT commands or data from the terminal while
dialing.
HANDSHAKE
When the modem handshakes it communicates with another modem to determine
the data rate the two modems use to communicate. Handshaking takes place at
the beginning of each connection between two modems. The originator and
answerer of a connection perform different actions while handshaking. The
modem does not accept AT commands or pass data from the terminal while hand-
shaking.
PS001907-0904
Operating Modes
ZILOG [ ZILOG, INC. ]
