Freescale Semiconductor MPC8260 - Manual (Page 1054)

ATM AAL1 Circuit Emulation Service
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
31-38 Freescale Semiconductor
Figure 31-27. Receive Buffers and BD Table Example
31.12 ATM Controller Buffers
Table 31-10 describes properties of the ATM receive and transmit buffers.
31.12.1 AAL1 CES RxBD
Figure 31-28 shows the AAL1 CES RxBD.
Table 31-10. Receive and Transmit Buffers
AAL
Receive Transmit
Size Alignment Size Alignment
AAL5 Multiple of 48 octets (except last buffer in frame) Double word aligned Any No requirement
AAL3/4 At least 44 octets (except last buffer in frame) Double word aligned At least 44 octets No requirement
AAL1/
AAL1
CES Multiple of 8 octets No requirement Multiple of 8 octets No requirement
AAL0 52-64 octets. Burst-aligned 52–64 octets. No requirement
BD memory space
RBD_Base
Rx BD table
of ch 1
Rx BD table
of ch 4
RBD_Offset
RBD_Base
RBD_Offset
Pointers
RxBD 1
RxBD 2
RxBD 3
RxBD 4
RxBD 5
RxBD 6
RxBD 7
RxBD 8
RxBD 9
RxBD 1
RxBD 2
RxBD 3
RxBD 4
RxBD 5
RxBD 6
Rx buffer 3 of
channel 1
Rx buffer 4 of
channel 1
Rx buffer 1 of
channel 4
Rx buffer 2 of
channel 4
Rx buffer 3 of
channel 4
Rx buffer 2 of
channel 1
Rx buffer 8 of
channel 4
•
•
•
•
•
•
Rx buffer 1 of
channel 1
Data memory space
from ch 1
entry of
RCT
Pointers
from ch 4
entry of
RCT