ATM Controller and AAL0, AAL1, and AAL5
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 30-71
30.10.5.3 ATM Controller Buffers

Table30-34 describes properties of the ATM receive and transmit buffers.

30.10.5.4 AAL5 RxBD

Figure 30-46 shows the AAL5 RxBD.

0x0A 0 BUSY The CP sets this bit wh en it tries to fetch buffer pointer with V bit cle ar.
FCCE[GBPB] is also set. Initialize to zero.
1RLI Red-line interrupt. Set by the CP when it fetches a buffer pointer with I = 1.
FCCE[GRLI] is also set. Initialize to zero.
2–7 Reserved, should be cleared.
8EPD Early packet discard.
0 Normal operation.
1 AAL5 frames in progress are received, but new AAL5 frames associated with
this pool are discarded. Can be used to implement EPD under core control.
9–15 Reserved, should be cleared.
0x0C — FBP_ENTRY Free buffer pool entry. Initialize with the first entry of the free buffer pool. Note that
FBP_ENTRY must be reinitialized with the entry pointed to by FBP_PTR when a
busy state occurs to reenable free buffer pool processing.
1Offset from FBT_BASE+RCT[BPOOL] × 16

Table30-34. Receive an d Transmit Buffers

AAL
Receive Transmit
Size Alignment Size Alignment
AAL5 Multiple of 48 octets (except last buffer in frame) Burst-aligned
(recommended)
Any No
requirement
AAL1 At least 47 octets Burst-aligned
(recommended)
47 octets No
requirement
AAL0 52-64 octets. Burst-aligned 52–64
octets
No
requirement
0123456789101112 131415
Offset + 0x00 EWILFCM CLP CNG ABRT CPUU LNE CRE
Offset + 0x02 Data Length (DL)
Offset + 0x04 Rx Data Buffer Pointer (RXDBPTR)
Offset + 0x06

Figure 30-46. AAL5 RxBD

Table30-33. Free Buffer Pool Parameter Table (continued)

Offset
1Bits Name Description