Motorola PowerQUICC II MPC8280 Series Reference Manual page 1204

AAL2 Parameter RAM
Table 33-12. SSSAR RxBD Field Descriptions (continued)
1
Offset Bits Name
0x02 — Data
Length
0x04 — RXDBPTR Rx data buffer pointer. Points to the address of the associated buffer. There are no
1
Boldfaced entries must be initialized by the user.
2
When RAS timer expires the RxBD is closed with RAS timer expired indication, the Last (L) bit is not set, and RXF
interrupt is not issued. A new RxBD is opened for the next incoming AAL2 packet and the frame is processed as
normal and is treated as a new frame. When the next SSSAR end-of-frame indication is received, the RxBD at that
time is closed with an L indication, and if RxQD[RFM] = 1, the receiver issues an RXF interrupt.
33.5 AAL2 Parameter RAM
When configured for ATM mode, the FCC parameter RAM is mapped as shown in
Table 33-13. The table includes both the fields for general ATM operation and also the
fields specific to AAL2 operation.
Note that some of the values must be initialized by the user, but values updated by the CP
should not be modified by the user.
Offset Name
0x00– —
0x3F
0x40 RCELL_TMP_BASE
0x42 TCELL_TMP_BASE
0x44 UDC_TMP_BASE
0x46 INT_RCT_BASE
0x48 INT_TCT_BASE
0x4A INT_TCTE_BASE
0x4C RAS_Timer_Duration
0x50 EXT_RCT_BASE
0x54 EXT_TCT_BASE
33-36
Freescale Semiconductor, Inc.
Contains the length of the buffer associated with this BD. If this is the last buffer (L=1)
of the SSSAR SDU, this field contains the total frame length.
byte-alignment requirements for the buffer, and it may reside in either internal or
external memory. This value is not modified by the CP.
Table 33-13. AAL2 Parameter RAM
Width
— Reserved. Should be cleared during initialization.
Hword Rx cell temporary base address. Points to a total of 64 bytes reserved
dual-port RAM area used by the CP. Should be 64 byte aligned.
User-defined. (Recommended address space: 0x3000–0x4000 or
0xB000–0xC000.)
Hword Tx cell temporary base address. Points to total of 64 bytes reserved
dual-port RAM area used by the CP. Should be 64-byte aligned.
User-defined.
(Recommended address space: 0x3000–0x4000 or 0xB000–0xC000.)
Hword UDC mode only. Points to a total of 32 bytes reserved dual-port RAM
area used by the CP. Should be 64-byte aligned. User-defined.
(Recommended address space: 0x3000–0x4000 or 0xB000–0xC000.)
Hword Internal receive connection table base. User-defined.
Hword Internal transmit connection table base. User-defined.
Hword Internal transmit connection table extension base. User-defined.
Word Contains the RAS_Timer duration in microseconds for the SSSAR
sublayer. User-defined.
Word External receive connection table base. User-defined.
Word External transmit connection table base. User-defined.
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