Motorola PowerQUICC II MPC8280 Series Reference Manual page 1072

ATM Memory Structure
Table 31-21. TCT Field Descriptions (continued)
Offset Bits Name
0x1C 0–1 —
2–7 PMT
8–15 TBD_BASE TxBD base. Points to the first BD in the channel's TxBD table. The 8 most-significant bits
0x1E 0–11
12 BNM
13 STPT
0x1E 14 IMK
15 PM
31.10.2.3.1 AAL5 Protocol-Specific TCT
Figure 31-31 shows the AAL5 protocol-specific TCT.
0
Offset + 0x10
Offset + 0x12
Offset + 0x14
Table 31-22 describes AAL5 protocol-specific TCT fields.
Table 31-22. AAL5-Specific TCT Field Descriptions
Offset Name
0x10 Tx CRC
0x14 Total Message Length
31-58
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Reserved, should be cleared.
Performance monitoring table. Points to one of the available 64 performance monitoring
tables. The starting address of the table is PMT_BASE+PMT × 32. Can be changed
on-the-fly.
of the address are taken from BD_BASE_EXT in the parameter RAM. The four
least-significant bits of the address are taken as zero.
Buffer-not-ready interrupt mask. Can be changed on-the-fly.
0 The transmit buffer-not-ready event of this channel is masked. (TBNR event is not
sent to the interrupt queue.)
1 The buffer-not-ready event of this channel is enabled.
Stop transmit. Should be cleared initially. When the host sets this bit, the CP deactivates
this channel and clears TCT[VCON] when the channel is next encountered in the APC
scheduling table. Note that for AAL5 if STPT is set and frame transmission is already
started (TCT[INF]=1), an abort indication will be sent (last cell with zero length field).
Interrupt mask. Can be changed on-the-fly.
0 The transmit buffer event of this channel is masked. (TXB event is not sent to the
interrupt queue.)
1 The transmit buffer event of this channel is enabled.
Performance monitoring. Can be changed on-the-fly.
0 No performance monitoring for this VC.
1 Performance is monitored for this VC. When a cell is sent for this VC, the performance
monitoring table indicated in PMT field is updated.
Total Message Length
Figure 31-31. AAL5 Protocol-Specific TCT
CRC32 temporary result.
This field is used by the CP.
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Description
Tx CRC
Description
15
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