DS3181 Maxim Integrated Products, DS3181 Datasheet - Page 118

• Manufacturer Part Number: DS3181
• Description: Network Controller & Processor ICs DS3-E3 ATM-Packet PH Y with Built-in Line
• Manufacturer: Maxim Integrated Products

Specifications of DS3181

• Product: Framer
• Number Of Transceivers: 1
• Data Rate: 44.736 Mbps
• Supply Voltage (max): 3.465 V
• Supply Voltage (min): 3.135 V
• Supply Current (max): 280 mA
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Package / Case: TEBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

DS3181/DS3182/DS3183/DS3184
10.5.1.2 Line Loopback (LLB)
Line loopback is enabled by setting PORT.CR4.LBM[2:0] = X10. DLB and LLB are enabled at the same time when
LBM[2:0] = 110, and only LLB is enabled when LBM[2:0] = 010.
The clock from the receive LIU or the RLCLK pin will be output to the transmit LIU or TCLKOn pin. The POS and
NEG data from the receive LIU or the RPOS and RNEG pin will be sampled with the receive clock to time it to the
LIU or pin interface.
When LLB is enabled, unframed all ones AIS can optionally be automatically enabled on the receive data path.
This AIS signal will be output on the RSERn pin in flexible fractional mode, and sent to the receive cell or packet
processor in framer modes, effectively stopping cell or packet data flow. When DLB and LLB is enabled, the AIS
signal will not be transmitted. See
Figure
10-10.
10.5.1.3 Payload Loopback (PLB)
Payload loopback is enabled by setting PORT.CR4.LBM[2:0] = 011.
The payload loopback copies the payload data from the receive framer to the transmit framer (before the fractional
logic) which then re-frames the payload before transmission. Payload loopback is operational in all framing modes
except “- OHM” modes.
When PLB is enabled, unframed all ones AIS transmission can optionally be automatically enabled on the receive
data path. This AIS signal will be output on the RSER pin in flexible fractional mode, and sent to the receive cell or
packet processor in framer modes, effectively stopping cell or packet data flow.
In all modes, the TSOFIn input pin is ignored.
The external transmit output pins TDENn and TSOFOn/TDENn can optionally be disabled by forcing a zero when
PLB is enabled.
In the framed modes, the data flow from the transmit cell or packet processor can be optionally disabled when PLB
is enabled. If the data flow is not disabled, the cells or packets from the system interface will be discarded. See
Figure
10-10.
10.5.1.4 Diagnostic Loopback (DLB)
Diagnostic loopback is enabled by setting PORT.CR4.LBM[2:0] = 1XX. DLB and LLB are enabled at the same time
when LBM[2:0] = 110, only DLB is enabled when LBM[2:0] = 10X or 111.
The Diagnostic loopback sends the transmit data, before line encoding, back to the receive side.
Transmit AIS can still be enabled using PORT.CR1.LAIS[2:0] even when DLB is enabled. See
Figure
10-10.
10.5.1.5 System Loopback (SLB)
System loopback is enabled by setting the PORT.CR4.SLB bit. The system loopback sends the packets or cells
from the transmit UTOPIA or POS-PHY interface back to the receive UTOPIA or POS-PHY interface. Cells and
packets from the line interface will be discarded. See
Figure
10-10.
10.5.2 Loss Of Signal Propagation
The Loss Of Signal (LOS) is detected in the line decoder logic if the device is set for HDB3 or B3ZS line encoding.
In unipolar (UNI) line interface modes and AMI modes LOS detection is disabled. The LOS signal from the line
decoder is sent to the DS3/E3 framer and the top level payload AIS logic except when DLB is activated. When DLB
is activated the LOS signal to the framer and AIS logic is never active. The LOS status in the line decoder status
register is valid in all frame and loopback modes, though it is always off in the line interface is in the UNI mode.
10.5.3 AIS Logic
There is AIS logic in both the framers and at the top level logic of the ports. The framer AIS is enabled by setting
the TAIS bit in the appropriate framer transmit control register (T3, E3-G.751, E3-G.832, or Clear Channel). The
top level AIS is enabled by setting the PORT.CR1.LAIS[2:0] bits (see
Table
10-18). The AIS signal is an unframed
all ones pattern or a DS3 framed 101010… pattern depending on the FM[5:0] mode bits. The DS3 Framed Alarm
Indication Signal (AIS) is a DS3 signal with valid F-bits, M-bits, and P-bits (P
and P
). The X-bits (X
and X
) are
1
2
1
2
set to one, all C-bits (C
) are set to zero, and the payload bits are set to a 1010 pattern starting with a one
XY
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