Freescale Semiconductor MPC8260 - Manual (Page 1132)

Inverse Multiplexing for ATM (IMA)
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
33-30 Freescale Semiconductor
33.4.4.1 IMA Group Transmit Table Entry
Table 33-5. IMA Group Transmit Table Entry
1
Offset Name Width Description
0x00 IGTCNTL Byte IMA group transmit control parameters.
0x01 IGTSTATE Byte IMA group transmit state. Microcode-managed parameter. Must be
initialized to zero at group start-up.
0x02 TGRPORDER Hword Offset of transmit group order table in DPRAM. Can be changed on the fly.
0x04 TVPHYNUM Byte Transmit Virtual PHY number. Maps this IMA transmit group to a virtual
PHY number for the purpose of selecting an ATM pace controller (APC)
table number for this IMA group. Note that this parameter must be unique;
it must not conflict with the PHY number of any non-IMA PHYs or with the
TVPHYNUM of any other IMA group.
If there are any PHY numbers which will never be used in a system (i.e. the
actual PHY with the address does not exist), then TVPHYNUM should be
selected from one of these PHYs. If no such PHY numbers are available
(i.e. the multi-PHY interface consists of the full 31 PHYs), then select
TVPHYNUM from one of the PHY numbers of the PHYs within this IMA
group.
0x05 TIFSN Byte Transmit IMA Frame Sequence Number (IFSN). Microcode-managed
parameter. Increments each time an IMA frame is transmitted, cycling from
0 through 255. Should be initialized to zero at group start-up.
0x06 TMCTR Byte Transmit IMA M counter. Microcode-managed parameter. Tracks IMA frame
boundaries. Increments once per round-robin distribution of cells to the
transmit queues, cycling from 0 through M. Initialize to zero at group startup.
0x07 TRLSTFCNT Byte TRL stuff frame counter. Microcode-managed parameter. Controls required
stuffing on the TRL. Decrements each time an ICP cell is sent on the TRL,
cycling from TRLSTFN through 0. A TRL stuff event occurs when it reaches
zero. Initialize to the value of TRLSTFN at group start-up.
0x08 TICPPTR Hword Offset of transmit ICP cell payload template area in DPRAM. Must be
64-byte aligned. This parameter and the associated template area may only
be changed when IGCNTL[ICPC]=IGTSTATE[ICPCA].
After changing TICPPTR, IGCNTL[ICPC] must be toggled.
0x0A TM Byte Transmit IMA frame size. Program to 31, 63, 127, or 255 for frame sizes (M)
of 32, 64, 128, or 256, respectively.
0x0B TRLSTFN Byte TRL stuff frame number. Defines the number of IMA frames sent between
TRL stuff events.
For ITC operation IGTCNT[CTC] = 0, program TRLSTFN = 2048/M. For
CTC operation IGTCNT[CTC] = 1, program TRLSTFN = (2048/M) – 1.
Refer to
Section 33.4.4.1.1, “IMA Group Transmit Control (IGTCNTL).”
0x0C TNUMLINKS Byte Number of transmit links in the IMA group that are in the active state
(ILTCNTL[TXSC]=01). Used by the APC to scale the rescheduling
parameters appropriately when rescheduling channels.
0x0D RTSTPCNT Byte Real time-stamp subcounter. Microcode-managed parameter, used by the
APC. Initialize to zero at group start-up.