M28529G-12 Mindspeed Technologies, M28529G-12 Datasheet - Page 106

• Manufacturer Part Number: M28529G-12
• Description: ATM IMA 8.192Mbps 1.8V/3.3V 484-Pin BGA
• Manufacturer: Mindspeed Technologies

Specifications of M28529G-12

• Package: 484BGA
• Utopia Type: Level 2
• Typical Operating Supply Voltage: 1.8|3.3 V
• Minimum Operating Supply Voltage: 1.71|3.135 V
• Maximum Operating Supply Voltage: 1.89|3.465 V
• Maximum Output Rate: 8.192 Mbps

Functional Description
consecutive header blocks are found, synchronization is declared. If any HEC calculation fails in the pre-sync state,
the process begins again (see
Figure
1-27). Synchronization will be held until seven consecutive incorrect HECs
are received. At this time, the “hunt” state is reinitiated.
Figure 1-27. Cell Delineation Process
1 Correct HEC
Pre-Sync
1 Errored HEC
6 Correct HECs
Hunt
7 Errored HECs
Sync
500027_006
During the sync state of cell delineation, cells are passed to the UTOPIA interface if the HEC is valid. If a single-bit
error in the header is detected, the error is corrected (optionally), and the cell is passed to the UTOPIA interface. If
HEC checking is enabled and HEC correcting is disabled (bit 3 in the CVAL register [0x0C]), cells with single-bit
HEC errors are discarded. If a multi-bit error is detected, the cell is dropped. Once either type of error is noted, all
subsequent errored cells are dropped until a valid cell is received. This rule applies even for single-bit errors that
could be corrected. Once a valid cell is detected, the process begins again. (See
Figure
1-28.)
When loss-of-cell delineation (LOCD) occurs, an interrupt is generated and the M2852x automatically enters the
“hunt” mode. However, the cell is still being scrambled by the far-end transmitter, leaving only the headers (or just
the HEC byte in Distributed Sample Scrambler [DSS]) unscrambled. This means that the only repetitive byte
patterns in the data stream that meet the cell delineation criteria are valid headers (or just the HEC bytes in DSS).
®
Mindspeed Technologies
28529-DSH-001-K
91
Mindspeed Proprietary and Confidential