RS8234
5.0 Reassembly Coprocessor
ATM ServiceSAR Plus with xBR Traffic Management
5.7 Reassembly Control and Status Structures
N8234DSC
PRELIMINARY
5-39
AAL_EN
Enable various cell processes. The AAL_EN field contains the following control bits:
PM_EN - - - - - Enable PM OAM processing on this channel.
FIFO_EN - - - - - Enable Logical FIFO mode.
LNK_EN - - - - - Enable writing of buffer descriptor NEXT field.
FW_EN - - - - - Enable firewall processing. Used in conjunction with FWALL_EN bit in RSM_CTR0.
M52_EN - - - - - If set high, all 52 octets of the cell are written to a cell buffer.
BINTR - - - - - Enable interrupt after BOM buffer filled in Message Mode.
STM_MODE - - - - - Enable Streaming Mode.
LECID_EN - - - - - Enable LANE-LECID echo suppression. Invalid in AAL3/4.
FRD_EN - - - - - Enable frame relay DE (Discard Eligibility) mode. Invalid in AAL3/4.
CLPD_EN - - - - - Enable CLP discard mode. Invalid in AAL3/4.
PDU_FLAGS
Set various flags related to PDUs. The PDU_FLAGS field contains the following control bits:
CNT_ROVR - - - - - Indication that SERVICE_CNT counters have rolled over. The next status entry
will indicate this condition.
SFPD_PND - - - - - Status Full Packet Discard Pending. Set when status queue is full, and CPCS
needs to be discarded when status entries available.
EPD - - - - - Early Packet Discard Flag. Set when EPD occurs on a channel. Cleared when new
packet starts and error condition cleared.
CI - - - - - Congestion Indication. PTI[1] header bit ORed across the CPCS-PDU.
CLP - - - - - Cell Loss Priority. CLP header bit ORed across the CPCS-PDU.
BFR_LOCAL - - - - - Buffer Local. If high, the current cell buffer is located in local memory;
otherwise, host memory. SAR maintains this bit.
BD_LOCAL - - - - - Buffer Descriptor Local. If high, the buffer descriptors reside in local memory;
otherwise, host memory. SAR maintains this bit.
ACT_PDU - - - - - Active PDU. Indication that at least one buffer has been taken off of the free
buffer queue for the current PDU being received.
BOM_BUF - - - - - BOM buffer flag. Set high when filling the first buffer of a PDU.
FFPD_PND - - - - - DMA FIFO Full Packet Discard Pending.
ABR_CTRL
Set various control bits related to QFC. The QFC_CTRL field contains the following control bits:
ER_EN - - - - - Enable ER operation.
ABR_VPC - - - - - Indicates ER connection is VPC (zero indicates VCC). For VPC operation, all VCC
entries in the VPC group except VCI=6, must be initialized with VPC_INDEX pointing to the VCC
entry corresponding with VCI=6. The VCI=6 entry contains the integrated EFCI bit over the VPC
group. Also, all entries in the VPC group including VCI=6 must set the ABR_VPC bit to a logic high.
TOT_PDU_LEN
Total PDU length in bytes.
TO_LAST
Indicates the last VCC table entry to process for time-out.
TO_EN
Enable time-out processing on the channel.
BASIZE
AAL3/4 BASize field. Used to record the BASize field from the AAL3/4 PDU, in order to check
against the LENGTH field in the AAL3/4 PDU trailer.
NEXT_ST
Next Segment Type expected.
Table 5-15. Reassembly VCC Table Descriptions (2 of 3)
Field Name
Description/Function
PM_EN
FIFO_EN
LNK_EN
FW_EN
M52_EN
BINTR
STM_MODE
LECID_EN
FRD_EN
CLPD_EN
CNT_ROVR SFPD_PND
EPD
CI
CLP
BFR_LOCAL BD_LOCAL
BOM_BUF
ACT_PDU
FFPD_PND
ER_EN
Reserved
ABR_VPC
Rsvd