DS3181 Maxim Integrated Products, DS3181 Datasheet - Page 119

• 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
immediately after each overhead bit. The DS3 framed AIS pattern is only available in DS3 modes. The unframed all
ones pattern is available in all framing and clear-channel modes including the DS3 modes. The transmit line
interface can send both unframed all ones AIS and DS3 framed AIS patterns from either the AIS generator in the
framer or the AIS generator at the top level.
The AIS signal generated in the framer can be initiated and terminated without introducing any errors in the signal.
When the unframed AIS signal is initiated or terminated, there will be no BPV or CV errors introduced, there will be
framing errors if a framed mode is enabled. When the DS3 framed AIS signal is initiated or terminated, in addition
to no BPV or CV errors, there should be no framing or P-bit (parity) or CP-bit errors introduced.
The AIS signal generated at the top level will not generate BPV errors but may generate P-bit and CP-bit errors
when the signal is initiated and terminated. The framed DS3 AIS signal will not cause the far end receiver to re-
sync when the signal is initiated, but it may cause a re-sync when terminated if the DS3 frame position in the
framer is changed while the DS3 AIS signal is being generated. A sequence of events can be executed which will
enable the initiation and termination of DS3 AIS or unframed all ones at the top level without any errors introduced.
The sequence will only work when the automatic AIS generation is not enabled. CV and P-bit errors can occur
when AIS is automatically generated and cannot be avoided. This sequence to generate an error free DS# AIS at
the top level is to have the DS3 AIS or unframed all ones signal initiate in the DS3 framer, and a few frames sent
before initiating or terminating the DS3 AIS or unframed all ones at the top level. After the top level AIS signal is
activated, the AIS signal in the framer can be terminated, DLB activated and diagnostic patterns generated. The
DS3 AIS signal generated at the top level will not change frame alignment after starting even if the DS3 frame
position in the framer is changed.
The transmit line AIS generator at the top level can generate AIS signals even when the framer is looped back
using DLB, but not when the line is looped back using LLB. The AIS signal generated in the framer will be looped
back to the receive side when DLB is activated.
The receive framer can detect both unframed all ones AIS and DS3 framed AIS patterns. When in DS3 framing
modes, both framed DS3 AIS and unframed all ones can be detected. In E3 framing modes E3 AIS, which is
unframed all ones, is detected. In clear-channel modes, unframed all ones is detected.
The receive payload interface going to the RSERn pin or the PLCP, FRAC, BERT or ATM/PKT logic can have an
unframed all ones AIS signal replacing the receive signal, this is called Payload AIS. The all ones AIS signal is
generated from either the DS3/E3 framer or the downstream top level unframed all ones AIS generator. The
unframed all ones AIS signal generated in the framer will be looped back to the transmit side when PLB is
activated. The unframed all ones AIS signal generated at the top level will be sent to the RSERn pin and other
receive logic, but not to the transmit side while PLB is activated. The top level AIS generator is used when a
downstream AIS signal is desired while payload loopback is activated and is enabled by default after rest and must
be cleared during configuration. Note that the downstream AIS circuit in the framer, when a DS3 mode is selected,
enforces the OOF to be active for 2.5 ms before activating when automatic AIS in the framer is enabled. The top
level downstream AIS will be generated with no delay when OOF is detected when automatic AIS at the top level is
enabled.
There is no detection of any AIS signal on the transmit payload signal from the TSERn pin or anywhere on the
transmit data path.
The transmit AIS generator at the top level can also be activated with a software bit or automatically when DLB is
activated. The receive AIS generator in the framer can be activated with a software bit, and automatically when
AIS, LOS or OOF are detected. The receive payload AIS generator at the top level can be activated with a software
bit or automatically when LOS, DS3/E3 OOF, LLB or PLB is activated.
When the port is configured for “- OHM” modes, the transmit DS3 AIS signal pattern generation is paused when the
TOHMI signal is active. Also the receive DS3 AIS and unframed all ones detectors do not use the bits marked for
overhead from the ROHMIn signal when DLB is not activated or the TOHMIn signal when DLB is activated. The
payload unframed all ones overwrites the receive signal with all ones even in overhead bit positions.
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