Inverse Multiplexing for ATM (IMA)
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 33-51
33.4.7.2 ICP Cell Reception Exceptions

ICP cells are received as AAL0 in the channel defined in RICPCH. Receive interrupts are provided for this

channel if enabled in its associated RCT.

Table33-23. IMA I nterrupt Queue Entry Field Descriptions

Offset Bits Name Description
Offset + 0 0 V Valid interrupt entry.
0 This interrupt queue entry is free and can be used by the CP.
1 This interrupt queue entry is valid. The host should read this interrupt and clear this bit.
1—Reserved.
2 W Wrap bit.When set, this is the last interrupt circular table entry. During initialization, the
host must clear all W bits in the table except the last one, which must be set.
3–4 — Reserved
5—Reserved
6 TQU Transmit queue underrun. Indicates that the corresponding PHY for this link requested a
cell for transmission, but the transmit queue was empty.
7 TQO Transmit queue overflow. Indicates that the TRL attempted to send a cell to this link’s
transmit queue, but no space was available.
8—Reserved
9 DSL DCB synchronization lost. This interrupt is issued when a link in a group with
IGRSTATE[GDSS] = 11 loses synchronization, and the link enters HUNT state at the
IFSM.
10 LS Link stalled. A link in the round-robin cell extraction process has excessively stalled and
been deactivated (i.e. switched to filler mode by the microcode).
11 DCBO Link out of delay synchronization. Set when the link’s DCB overflows, indicating that delay
synchronization for this link is not possible.
12 LDS Link delay synchronized. Set when delay synchronization is achieved for a link that has
been added to an existing group.
13 GDS Group delay synchronized. Set when a group achieves delay synchronization as part of
the group startup procedure.
14 IFSD IMA frame synchronization status = defect. Set when the associated link goes into the
Loss of IMA Frame Defect state of the Error/Maintenance State Machine.
15 IFSW IMA frame synchronization status = working. Set when the associated link goes into the
IMA Working state of the Error/Maintenance State Machine.
Offset + 2 0 L/G Link/group indicator. Indicates whether this interrupt is associated with a link or a group,
and thus if the NUM field is a link number or group number.
0 This interrupt is associated with a link.
1 This interrupt is associated with a group.
1–15 NUM Link or group number associated with this interrupt.