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CHAPTER 4 ATM CELL PROCESSOR
Preliminary User’s Manual S14767EJ1V0UM00
319
Word0
:The contents of Word0 in the packet descriptor read from SDRAM is stored as is.
The initial value must be all zeros.
:This bit is used internally by SAR processing. The initial value must always be 1.
:Specifies send priority .
111: CBR
110: VBR
101: ABR
010: UBR
100: GFR
:VPI/VCI values to be contained in the cell header
:Number of bytes of this packet that have been sent so far. The initial value is 0.
L
PRIORITY
VPI/VCI
NO.OF BYTE TRANSMITTED
IN THIS PACKET
REMAINING BYTES IN
CURRENT BUFFER
CRC-32 COUNT
:Number of bytes in the current buffer that have not been sent. The initial value is
0.
:CRC-32 value calculated for those cells of this packet that have been sent. The
final CRC-32 value is set in the CRC-32 field in the trailer.
:Pointer to the byte in the current buffer that is to be transferred next
:Pointer to the next buffer in the current packet directory
:Maximum Burst Size. The number of cells continuously transmitted with PCR.
Only used in VBR mode.
:Internally used for counting MBS0. Initially, the same value as MBS0 has to be
set. Only used in VBR mode.
:The number of the PHY which this VC transmits to.
:"Active" bit indicating whether the VC table is in the active or idle state.
1: Active state
0: Idle state
:Pointer to the Rx VC Table. This field is used in ABR only.
:Minimum Cell Rate. In VBR and GFR mode, SCR has to be set in this field.
:Peak Cell Rate.
:Initial Cell Rate. Only used in ABR mode.
:Allowed Cell Rate. Initially, the same value as ICR has to be set. Only used in
ABR mode.
:These fields are used internally for scheduling use.
:These fields are used internally for ABR use.
:The ACR Decrease Time Factor. This field is used in ABR only. The format is
following:
ADTF(millisecond) = 10*2
:The Cutoff Decrease factor. This field is used in ABR only. The format is following:
CDF0: 0-6 CDF=1/2
CDF0: 7 CDF=0
:The start address of the first Packet Info structure in transmit queue for this VC.
The initial value has to be 0.
:The start address of the last Packet Info structure in transmit queue for this VC.
The initial value has to be 0.
BUFFER READ ADDRESS
NEXT BUFFER ADDRESS
MBS0
MBS
PHY NO.
A
Rx VC Number
MCR
PCR
ICR
ACR
WORD 10
WORD 11 & WORD 12
ADTF0
ADTF
CTF0
CDF
FIRST PACKET INFO
LAST PACKET INFO