Motorola PowerQUICC II MPC8280 Series Reference Manual page 1249

Table 34-14 describes the format of a receive group order table entry.
Table 34-14. Receive Group Order Table Entry Field Descriptions
Bits Name
0–2 — Reserved, initialize to zero.
3–7 PHY PHY address (up to 31 PHYs[0–30]) of the link transmitting in this position in the round-robin.
ADDRESS A value of 0x1F in this field indicates the end of the group order table.
34.4.5 IMA Link Tables
The IMA link tables consist of multiple IMA group structures indexed by the PHY address
of their corresponding PHYs. The transmit and receive parameters are located in separate
tables. The IMA group transmit and receive table entries are each 32 bytes long.
Note that to conserve memory space consumed by these tables, it is best to group the
addresses of the PHYs that are assigned as IMA. [For example, if out of eight total links
only four are IMA, then optimally these would be links 0 through 3.]
34.4.5.1 IMA Link Transmit Table Entry
Table 34-15. IMA Link Transmit Table Entry
Offset Name
0x00 ILTCNTL
0x01 ILTSTATE
0x02 LICPOS
0x03 ILID
0x04 ITSEC
0x08 ITQSP
0x0A ITQEP
MOTOROLA
Freescale Semiconductor, Inc.
Width
Byte IMA link transmit control parameters.
Byte IMA link transmit state. Microcode-managed parameter. Initialize to
zero at link startup.
Byte Link ICP offset. Determines the position of the ICP cell within the IMA
frame. Program in the range 0 to M-1. See the IMA specification for
recommended methods for programming this field.
Byte IMA link ID. Formatted per the Cell ID and Link ID field of an ICP cell.
Bit 0: 1 (indicating ICP cell)
Bits 1-2: Not Used, set to zero
Bits 3-7: Program to software-assigned LID.
[Note: This value is only used by microcode to format ICP cells for this
link, it is not used to determine round-robin transmission order. That
function is performed by the group order table.]
Word IMA transmit stuff event counter. While ILTCNTL[SES]=0, increments
each time a stuff event is performed on this link. Initialize to zero at link
startup.
Hword IMA link transmit queue start pointer. This parameter forms bits 12-27
of the pointer; bits 0-11 are from IMAEXTBASE, and bits 28-31 are
zero. Refer to Section 34.4.6.1, "Transmit Queues".
Hword IMA link transmit queue end pointer. This parameter forms bits 12-27
of the pointer; bits 0-11 are from IMAEXTBASE, and bits 28-31 are
zero. Points to the last cell in the transmit queue. Program this
parameter to ITQSP+TQ_SIZE-4. Refer to Section 34.4.6.1, "Transmit
Queues".
Chapter 34. Inverse Multiplexing for ATM (IMA)
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IMA Programming Model
Description
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Description
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