Freescale Semiconductor MPC8260 - Manual (Page 1145)

Inverse Multiplexing for ATM (IMA)
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 33-43
33.4.5.1.2 IMA Link Transmit State (ILTSTATE)
The fields of the ILTSTATE register are shown in Figure 33-22
Table 33-17 describes the ILTSTATE bit fields.
33.4.5.1.3 IMA Transmit Interrupt Status (ITINTSTAT)
The fields of the ITINTSTAT register are shown in Figure 33-23 .
3-4 TXSC Transmit status/control. Sets the transmit mode of the IMA link.
00 Filler mode. The IMA link transmits only ICP and filler cells, no data cells.
01 Active mode. The IMA link is capable of sending data cells.
1X Reserved.
5-7 IGNUM Determines to which IMA group this link belongs. Contains the number of the link’s associated
IMA Group Table entry.
Note: This value need not be the same as the group’s IMA ID; the IMA ID is programmed
separately in the group’s ICP cell template.
0 1 2 3 4 5 7
Field LSTF LIMSTf LSTFIP LGSU TQSU LDC —
Figure 33-22. IMA Link Transmit State (ILTSTATE)
Table 33-17. ILTSTATE Field Descriptions
Bits Name Description
0 LSTF Link stuff flag. Microcode-managed parameter. Indicates that the next ICP cell on this link will
be part of a stuff event. Initialize to zero at link startup.
1 LIMSTF Link imminent stuff flag. Microcode-managed parameter. Indicates that an upcoming stuff
event will be signalled in the next ICP of this link (via LSI=001). Initialize to zero at link startup.
2 LSTFIP Link stuff-in-progress flag. Microcode-managed parameter. Indicates that the next cell on this
link will be the second cell of a stuff event. Initialize to zero at link startup.
3 LGSU Link/group startup flag. Microcode-managed parameter. Will be set by the microcode after the
link’s transmit queue has reached target average depth of 3 cells. While this bit is cleared, the
link will transmit only filler cells. Initialize to zero at link startup.
4 TQSU Transmit queue startup flag. Microcode-managed parameter. Will be set by the microcode after
the first cell has been sent to the transmit queue. Initialize to zero at link startup.
5 LDC Link Due Cell - Link is due cell from round robin distribution. Microcode managed parameter
initialize to 0. Used for optional TRL Service Latency enhancement only.
6-7 — Reserved, initialize to zero.
0 3 4 5 6 7
Field — PTQO TQO PTQU TQU
Figure 33-23. IMA Transmit Interrupt Status (ITINTSTAT)
Table 33-16. ILTCNTL Field Descriptions (continued)
Bits Name Description