XRT79L71 Datasheet, PDF (358/441 Pages) Exar Corporation – 1 - CHANNEL DS3/E3 ATM UNI/PPP COMBO IC

XRT79L71
REV. P1.0.3
PRELIMINARY
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1 - CHANNEL DS3/E3 ATM UNI/PPP COMBO IC
BIT NUMBER
NAME
TYPE
DESCRIPTION
4
GFC Insertion Enable - R/W GFC Insertion Enable - Bit 2:
Bit 2
This READ/WRITE bit-field along with GFC Insertion Enable - Bits 3,
1 and 0 permit the user to select the bits (within the GFC nibble of
each "outbound" ATM cell) that will be modified by the contents that
is applied via the "Transmit GFC Serial Input" port, as described
below.
0 - Configures the Transmit GFC Serial Input" port to NOT modify the
contents of Bit 2 within the GFC nibble.
1 - Configures the Transmit GFC Serial Input" port to modify the con-
tents of Bit 2 (within the GFC nibble) with the value that is applied via
the Transmit GFC Serial Input Port.
3
GFC Insertion Enable - R/W GFC Insertion Enable - Bit 1:
Bit 1
This READ/WRITE bit-field along with GFC Insertion Enable - Bits 3,
2 and 0 permit the user to select the bits (within the GFC nibble of
each "outbound" ATM cell) that will be modified by the contents that
is applied via the "Transmit GFC Serial Input" port, as described
below.
0 - Configures the Transmit GFC Serial Input" port to NOT modify the
contents of Bit 3 (the most significant bit) within the GFC nibble.
1 - Configures the Transmit GFC Serial Input" port to modify the con-
tents of Bit 3 (within the GFC nibble) with the value that is applied via
the Transmit GFC Serial Input Port.
2
GFC Insertion Enable - R/W GFC Insertion Enable - Bit 0 (LSB):
Bit 0
This READ/WRITE bit-field along with GFC Insertion Enable - Bits 2
through 0 permit the user to select the bits (within the GFC nibble of
each "outbound" ATM cell) that will be modified by the contents that
is applied via the "Transmit GFC Serial Input" port, as described
below.
0 - Configures the Transmit GFC Serial Input" port to NOT modify the
contents of Bit 0 (the least significant bit) within the GFC nibble.
1 - Configures the Transmit GFC Serial Input" port to modify the con-
tents of Bit 0 (within the GFC nibble) with the value that is applied via
the Transmit GFC Serial Input Port.
1
COSET Polynomial Addi- R/W COSET Polynomial Addition:
tion
This READ/WRITE bit-field permits the user to configure the Trans-
mit ATM Cell Processor block to modulo-add the COSET Polynomial
(e.g., x^6 + x^4 + x^2 + 1) to the HEC byte value, within each "out-
bound" ATM cell.
0 - Configures the Transmit ATM Cell Processor block to NOT mod-
ulo-add the COSET Polynomial to the HEC byte within each out-
bound ATM cell.
1 - Configures the Transmit ATM Cell Processor block to modulo-add
the COSET Polynomial to the HEC byte within each outbound ATM
cell.
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