XRT79L71 Datasheet, PDF (432/441 Pages) Exar Corporation – 1 - CHANNEL DS3/E3 ATM UNI/PPP COMBO IC

XRT79L71
REV. P1.0.3
PRELIMINARY
áç
1 - CHANNEL DS3/E3 ATM UNI/PPP COMBO IC
TRANSMIT ATM CELL PROCESSOR BLOCK - TRANSMIT USER CELL FILTER # 3 - CHECK REGISTER -
BYTE 1 (ADDRESS = 0X1F68)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Transmit User Cell Filter # 3 - Check Register - Byte 1 [7:0]
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
0
BIT NUMBER
NAME
7-0
Transmit User Cell
Filter # 3 - Check
Register - Header Byte 1
TYPE
R/W
DESCRIPTION
Transmit User Cell Filter # 3 - Check Register - Header Byte
1:
The User Cell filtering criteria (for Transmit User Cell Filter # 3) is
defined based upon the contents of 9 read/write registers.
These registers are the four "Transmit ATM Cell Processor Block
- Transmit User Cell Filter # 3 - Pattern Registers", the four
"Transmit ATM Cell Processor Block - Transmit User Cell Filter #
3 - Check Registers" and the "Transmit ATM Cell Processor
Block - Transmit User Cell Filter # 3 Control Register.
This READ/WRITE register, along with the "Transmit ATM Cell
Processor Block - Transmit User Cell Filter # 3 - Pattern Register
- Header Byte 1" permits the user to define the User Cell Filter-
ing criteria for "Octet # 1" within the incoming User Cell. More
specifically, these READ/WRITE register bits permit the user to
specify which bit(s) in "Octet 1" of the incoming user cell (in the
Transmit ATM Cell Processor Block) are to be checked against
the corresponding bit-fields within the "Transmit ATM Cell Pro-
cessor Block - Transmit User Cell Filter # 3 - Pattern Register -
Header Byte 1" 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
Transmit User Cell Filter to check and compare the correspond-
ing bit in "Octet # 1" (of the incoming user cell) with the corre-
sponding bit in the "Transmit ATM Cell Processor Block -
Transmit User Cell Filter # 3 - Pattern Register - Header Byte 1".
Writing a "0" to a particular bit-field in this register causes the
Transmit User Cell Filter to treat the corresponding bit within
"Octet # 1" (in the incoming user cell) as a "don't care" (e.g., to
forgo the comparison between the corresponding bit in "Octet #
1" of the incoming user cell with the corresponding bit-field in the
"Transmit ATM Cell Processor Block - Transmit User Cell Filter #
3 - Pattern Register - Header Byte 1").
420