73K224BL
V.22bis, V.22, V.21, Bell 212A, 103
Single-Chip Modem w/ Integrated Hybrid
DATA SHEET
CONTROL REGISTER 2
CR2
D7
0
D6
D5
D4
D3
D2
D1
D0
ADDR
100
SPEC REG
ACCESS
CALL INIT TRANSMIT S1
16 WAY
TRAIN
INHIBIT
EQUALIZER
ENABLE
RESET
DSP
BIT
NAME
Equalizer
Enable
CONDITION
DESCRIPTION
The adaptive equalizer is in its initialized state.
D0
0
1
The adaptive equalizer is enabled. This bit is used in
handshakes to control when the equalizer should calculate
its coefficients.
D1
D2
Train Inhibit
0
1
0
1
The adaptive equalizer is active.
The adaptive equalizer coefficients are frozen.
The DSP is inactive and all variables are initialized.
RESET DSP
The DSP is running based on the mode set by other control
bits.
D3
D4
16 Way
0
1
0
The receiver and transmitter are using the same decision
plane (based on the modulator control mode).
The receiver, independent of the transmitter, is forced into a
16 point decision plane. Used for QAM handshaking.
Transmit S1
The transmitter when placed in alternating mark/space
mode transmits 0101...... scrambled or not dependent on
the bypass scrambler bit.
1
0
1
When this bit is 1 and only when the transmitter is placed in
alternating mark/space mode by CR1 bits D7, D6, and in
DPSK or QAM, an unscrambled repetitive double di-bit
pattern of 00 and 11 at 1200 bit/s (S1) is sent.
D5
Call Init
The DSP is set-up to do demodulation and pattern
detection based on the various mode bits. Both answer
tones are detected in demodulation mode concurrently; TR-
D0 is ignored.
The DSP decodes unscrambled mark, answer tone and call
progress tones.
D6
D7
Special
Register
Access
0
1
Normal CR3 access.
Setting this bit and addressing CR3 allows access to the
special register (see the special register for details).
Not used at this time
0
Only write zero to this bit.
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© 2005, 2008 TERIDIAN Semiconductor Corporation
Rev 7.1