Freescale Semiconductor MPC8260 - Manual (Page 1160)

Inverse Multiplexing for ATM (IMA)
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
33-58 Freescale Semiconductor
33.4.10 Changing IMA Version
A new CPCR command has been added to the IMA microcode to change the IMA version on-the-fly
without software intervention. Use the following procedure:
1. Before issuing the command, the user should initialize the COMM_INFO fields in the parameter
RAM as described in Figure 33-31 .
2. To issue this FCC command, refer to Section 14.4, “Command Set.” Use opcode 1110(0xE).
m
m
3. Wait for the CPCR[FLG] to be cleared by the CPM before issuing a new CP command. Refer to
Section 14.4, “Command Set.”
33.5 IMA Software Interface and Requirements
33.5.1 Software Model
The IMA microcode facilitates the implementation of the lower levels of an IMA system. Host software
(from here on, “host software” is code running on the G2 core) is responsible for initializing PowerQUICC
II IMA data structures, establishing and tearing down connections, handling of alarms, keeping statistics,
and controlling protocol state machines. The IMA microcode interfaces to the software-implemented
(Layer Management and Plane Management) functions by providing received ICP cells and by interrupts.
The software-implemented functions control the microcode and the system via the IMA root, group, and
link parameters and by providing an ICP cell template to the microcode for ICP cell transmission.
0 8 9 11 12 15
0x86 — ITG —
0x88 Filler CRC
0x8A — IV
Figure 33-31. COMM_INFO Field
Table 33-29. COMM_INFO Field Descriptions
Offset Bits Name Description
0x86 0–8 — Reserved, should be cleared.
9–11 ITG IMA transmit group. Program to the IMA group number [0–7] multiplied by 16 bytes. For
example, if the IMA group number = 3, program ITG to 0x30.
12–15 — Reserved, should be cleared.
0x88 0–15 Filler CRC Filler cell CRC. Set to 0xC602 (for IMA version 1.0) or 0xD902 (for IMA version 1.1)
0x8A 0–13 — Reserved, should be cleared.
14–15 IV IMA version
00 Reserved
01 IMA version 1.0
10 Reserved
11 IMA version 1.1