73K224L
V.22bis, V.22, V.21, Bell 212A, 103
Single-Chip Modem
DATA SHEET
DETECT REGISTER (continued)
D7
D6
D5
D4
D3
D2
D1
D0
RECEIVE
LEVEL
INDICATOR
S1
PATTERN
DETECT
RECEIVE
DATA
UNSCR.
MARK
DETECT
CARR.
DETECT
ANSWER
TONE
DETECT
CALL
PROG.
SIGNAL
QUALITY
INDICATOR
DR
010
BIT NO.
NAME
CONDITION
DESCRIPTION
No answer tone detected.
D2
Answer Tone
Received
0
1
In Call Init mode, indicates detection of 2225 Hz answer
tone in Bell mode (TR bit D0=0) or 2100 Hz if in CCITT
mode (TR bit D0=1). The device must be in originate mode
for detection of answer tone. Both answer tones are
detected in demod mode.
D3
D4
Carrier Detect
0
1
No carrier detected in the receive channel.
Indicated carrier has been detected in the received
channel.
Unscrambled
Mark Detect
0
1
No unscrambled mark.
Indicates detection of unscrambled marks in the received
data. Should be time qualified by software.
D5
D6
Receive Data
Continuously outputs the received data stream. This data is
the same as that output on the RXD pin, but it is not
disabled when RXD is tri-stated.
S1 Pattern
Detect
0
1
No S1 pattern being received.
S1 pattern detected. Should be time qualified by software.
S1 pattern is defined as a double di-bit (001100..)
unscrambled 1200 bit/s DPSK signal. Pattern must be
aligned with baud clock to be detected.
D7
Receive Level
Indicator
0
1
Received signal level below threshold, (typical ≈ -25 dBm0); can
use receive gain boost (+18 dB).
Received signal above threshold.
TONE REGISTER
D7
D6
D5
D4
D3
D2
D1
D0
RXD
OUTPUT
CONTR.
TRANSMIT
GUARD
TONE
TRANSMIT
ANSWER
TONE
TRANSMIT
DTMF
DTMF 3
DTMF 2
DTMF 1/
EXTENDED
OVER- SPEED
DTMF 0/
ANSWER/
GUARD
TR
011
BIT NO.
NAME
CONDITION
DESCRIPTION
D6 D5 D4 D0 D0 interacts with bits D6, D5, and D4 as shown.
D0
DTMF 0/
Answer/ Guard
Tone
X
X
X
1
1
0
X
0
Transmit DTMF tones.
Select Bell mode answer tone. Interacts with DR bit D2 and
TR bit D5.
X
1
0
1
Select CCITT mode answer tone. Interacts with DR bit D2
and TR bit D5.
Page: 11 of 31
© 2005, 2008 TERIDIAN Semiconductor Corporation
Rev 7.1
TERIDIAN [ TERIDIAN SEMICONDUCTOR CORPORATION ]
