XRT79L71_1 Datasheet, PDF (279/434 Pages) Exar Corporation – 1-CHANNEL DS3/E3 ATM UNI/PPP/CLEAR-CHANNEL FRAMER IC -

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XRT79L71
1-CHANNEL DS3/E3 ATM UNI/PPP/CLEAR-CHANNEL FRAMER IC - REGISTER/MAP DESCRIPTION
BIT NUMBER
NAME
7-0
Receive User Cell Filter #
0 - Check Register -
Header Byte 2
TYPE
R/W
DESCRIPTION
Receive User Cell Filter # 0 - Check Register - Header Byte
2:
The User Cell filtering criteria (for Receive User Cell Filter # 0) is
defined based upon the contents of 9 read/write registers.
These registers are the four Receive ATM Cell Processor Block -
Receive User Cell Filter # 0 - Pattern Registers, the four Receive
ATM Cell Processor Block - Receive User Cell Filter # 0 - Check
Registers and the Receive ATM Cell Processor Block - Receive
User Cell Filter # 0 Control Register.
This READ/WRITE register, along with the Receive ATM Cell
Processor Block - Receive User Cell Filter # 0 - Pattern Register
- Header Byte 2 permits the user to define the User Cell Filtering
criteria for Octet # 2 within the incoming User Cell. More specifi-
cally, these READ/WRITE register bits permit the user to specify
which bit(s) in Octet 2 of the incoming user cell (in the Receive
ATM Cell Processor Block) are to be checked against the corre-
sponding bit-fields within the Receive ATM Cell Processor Block
- Receive User Cell Filter # 0 - Pattern Register - Header Byte 2
by the User Cell Filter, when determine whether to filter a given
User Cell.
Writing a "1" to a particular bit-field in this register, forces the
Receive User Cell Filter to check and compare the correspond-
ing bit in Octet # 2 (of the incoming user cell) with the corre-
sponding bit in the Receive ATM Cell Processor Block - Receive
User Cell Filter # 0 - Pattern Register - Header Byte 2.
Writing a "0" to a particular bit-field in this register causes the
Receive User Cell Filter to treat the corresponding bit within
Octet # 2 (in the incoming user cell) as a don't care (e.g., to forgo
the comparison between the corresponding bit in Octet # 2 of the
incoming user cell with the corresponding bit-field in the Receive
ATM Cell Processor Block - Receive User Cell Filter # 0 - Pattern
Register - Header Byte 2).
Receive ATM Cell Processor Block - Receive User Cell Filter # 0 - Check Register - Byte 3 (Address =
0x174A)
Bit 7
R/W
0
Bit 6
R/W
0
Bit 5
Bit 4
Bit 3
Bit 2
Receive User Cell Filter # 0 - Check Register - Byte 3 [7:0]
R/W
R/W
R/W
R/W
0
0
0
0
Bit 1
R/W
0
Bit 0
R/W
0
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