73K222AL
V.22, V.21, Bell 212A, 103
Single-Chip Modem
DATA SHEET
DETECT REGISTER (continued)
D7
X
D6
X
D5
D4
D3
D2
D1
D0
DR
RECEIVE
UNSCR.
CARR.
ANSWER
CALL
LONG
010
DATA
MARK
DETECT
TONE
PROG.
LOOP
BIT NO.
D2
NAME
CONDITION
DESCRIPTION
No answer tone detected.
Indicates detection of 2225 Hz answer tone in Bell mode
or 2100 Hz in CCITT mode. The device must be in
originate mode for detection of answer tone. For CCITT
answer tone detection, bit D0 of the Tone Register must
be set to a 1.
Answer Tone
0
1
Detect
D3
D4
Carrier
Detect
0
1
No carrier detected in the receive channel.
Indicates carrier has been detected in the receive
channel.
Unscrambled
Mark Detect
0
1
No unscrambled mark.
Indicates detection of unscrambled marks in the received
data. A valid indication requires that unscrambled marks
be received for > 165.5 ± 6.5 ms.
D5
Receive Data
Not Used
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.
D6, D7
Undefined
D5
Not used. Mask in software.
TONE REGISTER
D7
D6
D4
D3
D2
D1
D0
RXD
TRANSMIT
GUARD
TONE
TRANSMIT
ANSWER
TONE
TRANSMIT
DTMF
DTMF 3
DTMF 2
DTMF 1/
OVER-
SPEED
DTMF 0/
ANSWER/
GUARD
TR
OUTPUT
CONTR.
011
BIT NO.
D0
NAME
CONDITION
D6 D5 D4 D0
DESCRIPTION
D0 interacts with bits D6, D5, and D4 as shown.
Transmit DTMF tones.
Detects 2225 Hz in originate mode.
DTMF 0/
Answer/
X
X
X
0
1
0
X
0
Guard Tone
X
X
X
1
1
0
1
0
0
0
0
0
0
0
0
1
1
0
1
Transmits 2225 Hz in answer mode (Bell).
Detects 2100 Hz in originate mode.
Transmits 2100 Hz in answer mode (CCITT).
Select 1800 Hz guard tone.
1
Select 550 Hz guard tone.
D1
DTMF 1/
D4 D1
D1 interacts with D4 as shown.
Asynchronous DPSK +1.0% -2.5%.
Asynchronous DPSK +2.3% -2.5%.
Overspeed
0
0
0
1
Page: 12 of 27
© 2007 TERIDIAN Semiconductor Corporation
Rev 6.1
TERIDIAN [ TERIDIAN SEMICONDUCTOR CORPORATION ]
