73K224BL
V.22bis, V.22, V.21, Bell 212A, 103
Single-Chip Modem w/ Integrated Hybrid
DATA SHEET
TONE REGISTER (continued)
TR
D7
D6
D5
D4
D3
D2
D1
D0
ADDR
011
RXD
OUTPUT
CONTROL
TRANSMIT
GUARD
TONE
TRANSMIT
ANSWER
TONE
TRANSMIT
DTMF
DTMF 3
DTMF 2/
4-WIRE
FDX
DTMF 1/
EXTENDED
OVER-
DTMF 0/
ANSWER
GUARD
SPEED
BIT
NAME
CONDITION
DESCRIPTION
D5
D4
D0 D5 interacts with bits D4 and D0 as shown. Also interacts
with DR bit D2 in originate mode (see Detect Register
description).
D5
Transmit
0
1
0
0
X
0
Disables answer tone generator.
Answer Tone
In answer mode, a Bell 2225 Hz tone is transmitted
continuously when the transmit enable bit is set.
1
0
0
1
1
Likewise, a CCITT 2100 Hz answer tone is transmitted.
Disables guard tone generator.
D6
D7
Transmit
Guard Tone
Enables guard tone generator (see D0 for selection of
guard tones). Bit D4 must be zero.
RXD Output
Control
0
1
Enables RXD pin. Receive data will be output on RXD.
Disables RXD pin. The RXD pin reverts to a high
impedance with internal weak pull-up resistor.
Page: 16 of 33
© 2005, 2008 TERIDIAN Semiconductor Corporation
Rev 7.1
TERIDIAN [ TERIDIAN SEMICONDUCTOR CORPORATION ]
