Freescale Semiconductor MPC8260 - Manual (Page 1000)

ATM Controller and AAL0, AAL1, and AAL5
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
30-80 Freescale Semiconductor
30.10.5.14 AAL2 TxBDs
Refer to Section 32.3.5.5, “SSSAR Transmit Buffer Descriptor.”
30.10.5.15 AAL5, AAL1 User-Defined Cell—TxBD Extension
In user-defined cell mode, the AAL5 and AAL1 TxBDs are extended to 32 bytes; see Figure 30-53 .
NOTE
For AAL0 a complete cell, including the UDC header, is stored in the buffer;
the AAL0 BD size is always 8 bytes.
30.10.6 AAL1 Sequence Number (SN) Protection Table
The 32-byte sequence number protection table, pointed to by AAL1_SNPT_BASE in the ATM parameter
RAM, resides in dual-port RAM and is used for AAL1 only. The table should be initialized according to
Figure 30-54 .
Offset + 0x08 Extra Cell Header.
Used to store the user-defined cell’s extra cell header. The extra cell header can be 1–12 bytes long.
Offset + 0x14 Reserved (12 bytes)
Figure 30-53. User-Defined Cell—TxBD Extension
0 15
Offset + 0x00 0x0000
Offset + 0x02 0x0007
Offset + 0x04 0x000D
Offset + 0x06 0x000A
Offset + 0x08 0x000E
Offset + 0x0A 0x0009
Offset + 0x0C 0x0003
Offset + 0x0E 0x0004
Offset + 0x10 0x000B
Offset + 0x12 0x000C
Offset + 0x14 0x0006
Offset + 0x16 0x0001
Offset + 0x18 0x0005
Offset + 0x1A 0x0002
Offset + 0x1C 0x0008
Offset + 0x1E 0x000F
Figure 30-54. AAL1 Sequence Number (SN) Protection Table