Inverse Multiplexing for ATM (IMA)
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
33-60 Freescale Semiconductor
33.5.3.2 General Operation
React to received ICP cells. ICP cells are only received when their SCCI field cha nges, except the
first received ICP cel l
Report any NE and FE timing mode mismatches (ITC vs. CTC) to the Unit Management
33.5.3.3 Receive Link State Machine Control
Set up unassigned links, awaiting ICP cells
Define either as standard multi-PHY or as unassigned IMA link
Set up receive channel for ICP OAM cells for this link only
Create and initialize delay compensation buffer
Respond to received ICP cells. Extract and validate link/group parameters
—IMA ID
Link ID
Link ICP offset
IMA frame size (M)
After establishment of group, change receive channel for ICP OAM cells such that all links in the
group point to the same channel
Control link operation (via ILRCTNL[RXSC]) in coordination with link and group states
33.5.3.4 Receive Group State Machine Control
Coordinate receive links, using received ICP cells to identify a proposed group
Establish and validate group parameters in conjunction with the received link states and parameters
IMA version
—IMA ID
Group order table
Enable delay synchronization for the group, and react to its completion
Control group operation (via IGRCNTL[RXSC]) in coordination with group state
Signal receive group state via ICP cells of corresponding transmit group
33.5.3.5 Transmit Link State Machine Control
Define the IMA link
Define link parameters (e.g. IMA ID, Link ID, IMA frame size (M)) in coordination with IMA
group definition
Assign ICP offset
Create and initialize transmit queue
Control link operation (via ILTCNTL[TXSC]) in coordination with link and group states