mt90224 Zarlink Semiconductor, mt90224 Datasheet - Page 51

• Manufacturer Part Number: mt90224
• Description: 8-port Ima/tc Phy Device
• Manufacturer: Zarlink Semiconductor

3.2.14
A quick initialization sequence for the RX IMA Group could be as follows (default values can be used for some
registers).
(Note: The startup procedure below is to indicate the most important steps. A more detailed and complete sequence
can be found in the Zarlink IMA Core Software).For MT90222 only groups 0,1,2 and 3 are used.
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3.2.15
The MT90222/3/4 supports software controlled link addition to an existing RX link group. Such an addition can be
used to increase available bandwidth. The added link receives Filler cells until the Far End (FE) TX side is active.
During this time, the new link’s delay is measured and compared with the current operating limits. The link is either
rejected or accepted. The operational delay can be corrected if required as described in 3.3.13.6
Incrementing/Decrementing the Recombiner Delay. After synchronization is achieved, the added link can be
included in the recombiner algorithm using bit 4 or 12 of the RX Recombiner (0x0201-0x0208) register. The link
will be effectively included in the IMA Group when the corresponding bit in the Enable Recombiner Status
(0x02AD) register is set.
A link may also be added to an IMA Group when the first User cell is received. This is done by writing to the RX
Recombiner Delay Control (0x0283) register.
3.2.16
There are two reasons to deactivate a link:
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Both link deactivation procedures specified in the IMA specification are supported under the control of software.
The command to disable the recombination process for a link is issued by writing to bit 4 or 12 of the RX
Recombiner (0x0201-0x0208) register.
If the delay of the link to be removed is not the worst delay, then no pointer correction is required and the
recombiner bit (i.e., bit 4 or 12 of RX Recombiner (0x0201-0x0208) register) for the removed link should be set to
0.
If it is the worst case delay, then the pointer values could be corrected to reduce the amount of additional delay
introduced by the recombiner. To do this, the pointers need to be changed (advanced). This results in reducing the
number of cells (the amount of time) required for the recombiner process.
Configure the SRAM parameters using the SRAM Control (0x0299), RX External SRAM Control (0x0284)
and Global Debug bit in the ICP Cell RAM DEBUG (0x0108) registers
Configure the Cell delineation and IMA Frame State Machines parameters by writing to the Cell Delineation
(0x00C9), Loss of Delineation (0x00C8) and IMA Frame Delineation (0x00CA) registers
Write to the RX Link Control (0x00C0-0x00C7) register to select the RX options
Configure the RX serial port(s) by writing to the TDM RX Link Control (0x0700-0x070F) register
Configure the RX IMA UTOPIA port by writing to the UTOPIA Output Group PHY Enable (0x0011) and
UTOPIA Output Group Address (0x0008-0x000B) registers
Validate the IMA parameter values received over the TDM links and configure the link in IMA mode using the
RX Recombiner (0x0201-0x0208) and the RX Link Control (0x00C0 - 0x00C7) register
When ready, start the recombiner process by writing to the RX Recombiner (0x0201-0x0208) register
the bandwidth required decreases or
an existing link becomes faulty.
RX IMA Group Start-Up
Link Addition
Link Deletion
Zarlink Semiconductor Inc.
MT90222/3/4
51
Data Sheet