DS3181 Maxim Integrated Products, DS3181 Datasheet - Page 166

• 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
Figure 10-41. DS3 Sub-Frame Framer State Diagram
Sync
All 4 bit positions failed
Verify
Load
2 F-bits loaded
The multiframe framer checks for a multiframe boundary. When the multiframe framer identifies a multiframe
boundary, it updates the data path frame counters if either an OOF or OOMF condition is present. The multiframe
framer waits until a sub-frame boundary has been identified. Then, each bit position is checked for the multiframe
boundary. The multiframe boundary is found by identifying the three multiframe alignment bits (M-bits). Since there
are seven multiframe bits and three bits are required to identify the multiframe boundary, up to 9 checks may be
needed to find the multiframe boundary. Once the multiframe boundary is identified, it is checked in each
subsequent frame. The data path frame counters are updated if the three multiframe alignment bits are error free,
and an OOF or OOMF condition exists. If the multiframe framer checks more than 15 multiframe bit (X-bits, P-bits,
and M-bits) positions without identifying the multiframe boundary, the multiframe framer times out, and forces the
sub-frame framer back into the load state. See
Figure 10-42
for the multiframe framer state diagram.
10.10.4.1.2 Receive DS3 Performance Monitoring
Performance monitoring checks the DS3 frame for alarm conditions and errors. The alarm conditions detected are
OOMF, OOF, SEF, LOF, COFA, LOS, AIS, Idle, RUA1, and RDI. The errors accumulated are framing, P-bit parity,
C-bit parity (C-bit format only), and Far-End Block Error (FEBE) (C-bit format only) errors.
An Out Of Multiframe (OOMF) condition is declared when a multiframe alignment bit (M-bit) error has been
detected in two or more of the last four consecutive DS3 frames, or when a manual - is requested. An OOMF
condition is terminated when no M-bit errors have been detected in the last four consecutive DS3 frames, or when
the DS3 framer updates the data path frame counters. See
Figure 10-42
for the multiframe framer state diagram.
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