ATM AAL2
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 32-37
0xA4 EPAYLOAD Word Reserved payload. Initialize to 0x6A6A6A6A.
0xA8 Trm Word (ABR only) The upper bound on the time between F-RM cells for an
active source. TM 4.0 defines the Trm period as 100 msec. The Trm value
is defined by the system clock and the time stamp timer prescaler (See
RTSCR). For time stamp prescalar of 1µs, Trm should be set to 100
ms/1µs = 100,000.
0xAC Nrm Hword (ABR only) Controls the maximum cells the source may send for each
F-RM cell. Set to 32 ce lls.
0xAE Mrm Hword (ABR only) Controls the bandwidth between F-RM, B-RM and user data
cell. Set to 2 cells.
0xB0 TCR Hword (ABR only) Tag cell rate. The minimum cell rate allowed for all ABR
channels. An ABR channel whose ACR is less than TCR sends only
out-of-rate F-RM cells at TCR. Should be set to 10 cells/sec as defined
in the TM 4.0. Uses the ATMF TM 4.0 floating-point format. Note that the
APC minimum cell rate should be at least TCR.
0xB2 ABR_RX_TCTE Hword (ABR only) Points to total of 16 bytes reserved dual-port RAM area used
by the CP. Should be 16-byte aligned. User-defined.
0xB4 RxQD_Base_Ext Word Points to the base address of the external RxQD table. The actual
address of the first RxQD in the table is RxQD_Base_Ext + 512*4.
User-defined.
0xB8 RX_UDC_Base Word Valid only for AAL2 VCs. Points to the base of the RX UDC header table
that contains the UDC headers of the AAL2 VCs. The pointer to a VC
UDC header is: RX_UDC_Base + 16*CH# (where CH# is the ATM
channel number)
0xBC TX_UDC_Base Word Valid only for AAL2 VCs. Points to the base of the TX UDC header table
that contains the UDC headers of the AAL2 VCs. The pointer to a VC
UDC header is: TX_UDC_Base + 16*CH# (where CH# is the ATM
channel number)
0xC0–
0xDF
Reserved. Should be cleared during initialization.
0xE0 TCELL_TMP_BASE_EXT Word Transmit Cell Temporary base address. Points to a total of
64*last_AAL2_Ch# octets reserved in external memory for partially filled
cells. Note: TCELL_TMP_BASE_EXT must be on the same bus as the
all the AAL2 data buffers required for CPS, SSSAR and CID switching.
0xE4–
0xFB
Reserved. Should be cleared during initialization.
0xFC PAD_TMP_BASE Hword PAD template base address. Points to an internal memory area that
contains the zero cell template. Should be 64-byte aligned. User-defined.
0xFE Reserved. Should be cleared during initialization.
Table32-13. AAL2 Parameter RAM (continued)
Offset Name Width Description