User manual

Inverse Multiplexing for ATM (IMA)
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 33-19
Cell Reception Task
- Each IMA Link follows a Four-State Machine - Received ICP Cell (AAL0 specific channel) are processed by the driver to control the State Machine - According to the Link’s state, the Microcode executes different Tasks
Group Unassigned
Link IFSM Unsynchronized
Link Delay Unsynchronized
No Link Defect
IRLCNTL.GA=1 (Set by the driver)
Microcode Actions
- screen incoming cells - keep only ICP cells, discard other cells
Configuration to reach to move to next state
- Group & Link initialized by the driver based
on the ICP content ( Link’s M value, ICP
- screen incoming cells - search for one ICP cell - look for several lCP cells in expected
- IMA Frame Sequence Number Validation
IFSW INT generated (IMA_event) to the driver
- data ATM cell reception enable - “New Group Link Delay Synchro Algo” OR - “Added Link Delay Synchro Algo”
IGRSTATE.GDSS=1 (all links of the Group
- Group achieves delay synchronization
either GDS INT in case of Group Start Up
Procedure or
LDS INT in case of added Link
Set Rx Links/Groups to active mode
frame format)
position
generated the IFSW INT)