User's Manual

Company Confidential 36 Raveon Technologies Corp.
Mode 3 - CD OFF
In this mode, the CD pin is always negated.
Mode 4 - Output Data Framing
To enable the Output Data Framing feature, set ATR1 to 4, set ATS120 to the
number of mS for the Pre-Data Time, and ATS121 to the number of mS for the
Post-Data Time.
Ouput Data Framing is used when it is necessary for the serial terminal to wake
from sleep or enter an appropriate mode to receive data. In this mode, the
Carrier Detect handshaking line is nominally low and only goes high to signal that
data is being output. The Pre-Data and Post-Data time can be set from 0-254ms,
as indicated in the diagram below. The CD signal will normally stay low (near 0
volts), and when the Output Data Framing takes place, it will go high (about 3V).
If Output Data Framing is enabled, any other Carrier Detect and flow control
output configuration is ignored.