cx28380 Mindspeed Technologies, cx28380 Datasheet - Page 56

• Manufacturer Part Number: cx28380
• Description: Cn8380 Quad T1/e1 Line Interface
• Manufacturer: Mindspeed Technologies

29380-DSH-001-B
SENS
12, 22, 32, 42—Transmitter Configuration (TLIU_CR)
ALT_TR
TERM
PD
T_BOOST
PPT
PULSE[2:0]
ALT_TR
7
Receiver Sensitivity Select
attenuated by more than 12 dB (line loss). In some applications (i.e., noisy lines, short
haul only, etc.) it may be desirable to limit the receiver’s sensitivity so that loss of signal
is detected at a higher level (see
Alternate Transformer Select
transmitter transformer turns ratios. Normally, a turns ratio of 1:2 for the transmitter is
used. An alternate transformer with turns ratio of 1:1.36 can be selected to minimize
power dissipation
Transmitter Termination Select
compensate for the presence of an optional external termination resistor. The external
resistor is placed in parallel across XTIP/XRING on systems that must meet transmitter
return loss requirements. See
through
Power Down
power dissipation. In low power mode, XTIP/XRING, RPOSO/RNEGO, and RCKO
outputs are three-stated.
Transmit Level Boost
resistance added to the output by surge protection circuitry. Typical resistance values
are 5.6
Programmed Pulse Template
programmed pulse shape stored in the corresponding shape register, SHAPEn [addr n8
– nF], is used for transmission.
Transmit Pulse Template Select
XRING is shaped to meet the transmit pulse template according to the selected cable
TERM
0 = RALOS detected at approximately –23 dB
1 = RALOS detected at approximately –16 dB
0 = Normal transformer (1:2)
1 = Alternate transformer (1:1.36)
0 = no external transmit termination resistor used
1 = external transmit termination resistor used
0 = Channel is disabled, low power mode
1 = Channel is enabled, normal operation
0 = No compensation
1 = Compensation enabled
0 = Pulse template selected by PULSE[2:0]
1 = Programmed pulse shape in SHAPEn registers
6
Preliminary Information / Mindspeed Proprietary and Confidential
Ω
2-8
s in series with line side XTIP and XRING signals.
for return loss values.
—
Unused channels can be put into a low power mode in order to minimize
PD
5
Mindspeed Technologies
—
Adjusts the transmit output level to compensate for series
T_BOOST
—
The receiver can receive signals which have been
4
—
—
—
Figure
Adjusts the transmit output level for one of two possible
Enables custom transmit pulse transmission. The
—
Adjusts the transmit XTIP/XRING output amplitude to
Table
Each positive or negative pulse output on XTIP/
2-8, for resistor placement. See
2-1).
PPT
3
®
PULSE[2]
2
PULSE[1]
1
Tables 2-4
PULSE[0]
Registers
0
R/W
48