ZL30226 Datasheet, PDF (40/141 Pages) Zarlink Semiconductor Inc – 4/8/16 Port IMA/TC PHY Device for xDSL

ZL30226/7/8
Data Sheet
Hardware controls the following bytes of the ICP cell:
• Byte 5 - the HEC is always calculated and inserted by the ZL30226/7/8
• Byte 6 - the TX OAM Label is defined by the software and the value contained in this location is transmitted
in all ICP cells, Stuff Cells and Filler cells sent on all the links that are part of the corresponding TX IMA
group
• Byte 7 - the TX Link ID (0x0336 - 0x033D) registers are used to set the Link Logical ID and the cell type is
determined by the internal controller on a per link basis
• Byte 8 - the frame sequence number is controlled by an internal counter
• Byte 9 - the TX ICP Cell Offset (0x0310-0x0317) registers are used to set this value and is inserted on a per
link basis
• Byte 10 - the link Stuff indication is inserted automatically and the advance indication option is programmed
by the TX IMA Control (0x0321-0x0324) registers on a per link basis
• Byte 11 - the SCCI is controlled by internal circuitry. The SCCI is incremented by one for each transfer of the
TX ICP cell from the buffer area to the TX Cell RAM.
• Byte 13 - the value of M is programmed through the TX Group Control Mode (0x0300-0x0307) register
• Byte 14 - the TX Group Control Mode (0x0300-0x0307) register is used to set the Transmit Timing
Information and define the reference link
• Bytes 52 and 53 - the calculated CRC-10 Error Control bits are inserted automatically
Software controls all remaining bytes of the ICP cells. It also maintains and updates all bytes that are not directly
controlled by the ZL30226/7/8. A dedicated address is reserved for each ICP cell byte for each of the eight IMA
Groups. This permits direct access to any of the bytes stored in each of the eight ICP Cell registers. Refer to Table
2, ICP Cell Description, for details on the ICP cell byte contents.
To avoid updating or corruption problems, the internal copy of the ICP Cell cannot be directly accessed. ICP cells
are prepared in a buffer area (RAM inside the ZL30226/7/8) and transfer commands are issued to copy the content
of the ICP cell into the internal Cell RAM area and to start using this new ICP cell. The ZL30226/7/8 uses a flag
(status bit) to indicate that this transfer is underway. Changes should not be made to the content of the ICP cell in
the buffer area until the transfer to the internal memory is complete. The status bit is cleared during the transfer and
returns to’1’ on completion of the transfer. IMA Groups are controlled independently. When access to the ICP cell of
one group is prohibited, the other ICP cell buffer areas can still be updated. The TX ICP Cell Handler (0x0086) and
TX ICP Cell Interrupt Enable (0x0088) registers are used to initiate a transfer and enable an optional interrupt to
indicate when the process is complete.
The SCCI field is incremented by one for each transfer command performed which includes a change in at least one
byte of the ICP cell.
2.4.8 IMA Frame Programmable Interrupt
An optional interrupt is provided at the end of an IMA frame to simplify software implemented changes in the Group
Control and Status field. This interrupt can be enabled on an as required and per group basis to implement a frame
counter. The TX IMA Frame Indication (0x0087) and TX IMA Frame Interrupt Enable (0x0089) registers are used
for the end of frame indication and frame interrupt.
2.4.9 Filler Cell Definition
The content of the Filler cell is pre-initialized and conforms with the IMA Specification. The OAM label in the Filler
Cell is copied from the ICP cell, allowing both IMA 1.0 and IMA 1.1 to run simultaneously on the same device.
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