![](http://datasheet.mmic.net.cn/380000/-PD98405_datasheet_16745025/-PD98405_178.png)
CHAPTER 5 SAR FUNCTION
178
Tx VC TABLE
POINTER
Note
Pointer to the address of the transmit VC table.
When an FRM cell is received, the POINTER is used to specify the VC NUMBER (VC
table address excluding the lower 4 bits) of the VC table from which a turn-around BRM
cell is transmitted. It is set to enable the use of the ABR service by this VC.
ECI
Note
Flag for setting the CI bit of a turn-around BRM cell.
Setting the ECI bit to "1" enables the host to forcibly set the CI bit of the turn-around
BRM cell, to be sent back from this VC, to "1" (for test purposes). While the ECI bit is
set to "1," the CI bit of the turn-around BRM cell to be sent back from the VC is held at
"1." This bit must be initialized to "0." It is set to enable the use of the ABR service by
this VC.
ENI
Note
Flag for setting the NI bit of a turn-around BRM cell.
Setting the ENI bit to "1" enables the host to forcibly set the NI bit of the turn-around
BRM cell, to be sent back from this VC, to "1" (for test purposes). While the ENI bit is
set to "1," the NI bit of the turn-around BRM cell to be sent back from the VC is held at
"1." This bit must be initialized to "0." It is set to enable the use of the ABR service by
this VC.
ER enb
Note
Flag for setting the ER bit of a turn-around BRM cell.
Setting the ER enb bit to "1" enables the host to set the ER field of the turn-around
BRM cell, to be sent back from this VC, to a value from the EER field of the VC table
(for test purposes). The
μ
PD98405 compares the ER value of a received FRM cell with
the EER value of the VC table and sets a smaller value in the ER field of the turn-
around BRM cell. While the ER enb bit is set to "1," the ER field of the turn-around
BRM cell, to be sent back from this VC, is set with the ER or EER value, whichever is
smaller. The ER enb bit must be initialized to "0." It is set to enable the use of the ABR
service by this VC.
EER
Note
Explicit rate.
This bit is used to set the ER field of a turn-around BRM cell. While the ER enb bit is
set to "1," the ER field of the turn-around BRM cell, to be sent back from this VC, is set
with the ER or EER value, whichever is smaller. The EER bit must be initialized to "0."
It is set to enable the use of the ABR service by this VC.
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".