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CHAPTER 5 SAR FUNCTION
179
CIM
Channel indication mode.
This bit specifies whether the VC NUMBER or VPI/VCI value is to be set as the
indication of the end of reception of a packet to be stored into the mailbox.
1: VPI/VCI value (value reduced to a length of 16 bits using the VRR register)
0: VC NUMBER
RIF0
Note
Rate increase factor.
This factor is used to control the increase in the transmission rate due to RM cell
reception. RIF is represented as follows:
RIF = 1/2
RIF0
It is set to enable the use of the ABR service by this VC.
RDF0
Note
Rate decrease factor
This factor is used to control the decrease in the transmission rate. RDF is represented
as follows:
RDF = 1/2
RDF0
It is set to enable the use of the ABR service by the VC.
ABR
ABR bit.
This bit specifies whether this VC uses the ABR service.
1: ABR service
0: CBR, VBR, UBR service
MBL
Maximum burst size for multicell transfer
The
μ
PD98405 supports multicell transfer only in PCI bus mode. The maximum size
supported is 5 cells. The host must set the MBL in cell units. If the MBL is "000" or
"001", the multicell transfer function is disabled, and the
μ
PD98405 performs one-cell
transfer. If the MBL is "110" or "111," it is recognized as being "101," such that five-cell
transfer is supported. In the general-purpose bus mode, the MBL must be "000."
MAC
MAC address filtering offset.
This field is used to set the position of the 48-bit destination address within the packet
to use MAC address (destination address) filtering. The position is set as an offset
relative to the beginning of the packet. The relationships between the MAC field values
and the offsets relative to the beginning of the packet are as follows:
"00": 2 bytes (Ethernet
TM
LAN Emulation Data Frame)
"01": 4 bytes (Token-Ring LAN Emulation Data Frame)
"10": 6 bytes
"11": 10 bytes
Note
These fields are used only by a VC which uses the ABR service. These fields must all be reset to
"0" if the ABR bit is set to "0".