73K222AL
V.22, V.21, Bell 212A, 103
Single-Chip Modem
DATA SHEET
TONE REGISTER
D7
D6
D5
D4
D3
D2
D1
D0
RXD
TRANSMIT
GUARD
TONE
TRANSMIT
ANSWER
TONE
TRANSMIT
DTMF
DTMF 3
DTMF 2
DTMF 1/
OVER-
DTMF 0/
ANSWER/
GUARD
TR
OUTPUT
CONTR.
011
SPEED
BIT NO.
NAME
CONDITION
DESCRIPTION
D3, D2,
DTMF 3,
D3 D2 D1 D0
Programs 1 of 16 DTMF tone pairs that will be
transmitted when TX DTMF and TX enable bit (CR0, bit
D1) are set. Tone encoding is shown below:
D1, D0
2, 1, 0
0
1
0
1
0
1
0
1
KEYBOARD
DTMF CODE
TONES
EQUIVALENT
D3 D2 D1 D0
LOW HIGH
1
2
3
4
5
6
7
8
9
0
*
#
A
B
C
D
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
697
697
697
770
770
770
852
852
852
941
941
941
697
770
852
941
1209
1336
1477
1209
1336
1477
1209
1336
1477
1336
1209
1477
1633
1633
1633
1633
Transmit
DTMF
D4
D5
0
1
Disable DTMF.
Activates DTMF. The selected DTMF tones are
transmitted continuously when this bit is high. TX DTMF
overrides all other transmit functions.
D5 interacts with bits D4 and D0 as shown.
Disables answer tone generator.
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.
Transmit
D5
0
1
D4 D0
0
0
Answer Tone
X
0
1
0
1
Likewise a 2100 Hz answer tone will be transmitted.
Page: 13 of 27
© 2007 TERIDIAN Semiconductor Corporation
Rev 6.1
TERIDIAN [ TERIDIAN SEMICONDUCTOR CORPORATION ]
