73K222BL
V.22, V.21, Bell 212A, 103 Single-Chip
Modem with Integrated Hybrid
DATA SHEET
TONE REGISTER (continued)
D7
D6
D5
D4
D3
D2
D1
D0
TR
011
RXD
OUTPUT
CONTR.
TRANSMIT TRANSMIT TRANSMIT DTMF 3 DTMF 2 DTMF 1/
DTMF 0/
ANSWER/
GUARD
GUARD
TONE
ANSWER
TONE
DTMF
OVER-
SPEED
BIT NO.
NAME
DTMF 3, 2, 1, 0
CONDITION
DESCRIPTION
Programs 1 of 16 DTMF tone pairs that will be
transmitted when TX DTMF (TONE, Bit D4) and TX
ENABLE bit (CR0, Bit D1) are set. Tone encoding is
shown below:
D3, D2,
D1, D0
KEYBOARD
TONES
DTMF CODE
EQUIVALENT
LOW
HIGH
D3 D2 D1 D0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
2
3
697
697
697
1209
1336
1477
4
5
6
7
8
9
0
*
#
A
B
C
D
770
770
770
852
852
852
941
941
941
697
770
852
941
1209
1336
1477
1209
1336
1477
1336
1209
1477
1633
1633
1633
1633
Disable DTMF.
Transmit DTMF
D4
0
1
Activates DTMF. The selected DTMF tones are
transmitted continuously when this bit is high and TX
ENABLE (CR0, Bit 1) is set to one. TX DTMF
overrides all other transmit functions.
Transmit
Answer Tone
D5
D5 D4 D0
D5 interacts with bits D4 and D0 as shown.
Disables answer tone generator.
0
1
0
0
X
0
Enables answer tone generator. A 2225 Hz answer
tone will be transmitted continuously when the
TRANSMIT ENABLE bit is set in CR0. The device
must be in answer mode.
1
0
1
Likewise a 2100 Hz answer tone will be transmitted.
Page: 13 of 26
© 2005, 2008 TERIDIAN Semiconductor Corporation
Rev 7.2
TERIDIAN [ TERIDIAN SEMICONDUCTOR CORPORATION ]
