
Agere Systems Inc.
161
Data Sheet
May 2001
155/622/2488 Mbits/s Data Interface
TDAT042G5 SONET/SDH
Register Descriptions
(continued)
UT Registers
(continued)
UT Provisioning Registers (R/W)
(continued)
Table 63. Registers 0x0211, 0x0215, 0x0219, 0x021D: Channel [A
—
D] Ingress Provisioning Register (R/W)
Reset default of registers = 0x361F.
Table 64. Registers 0x0212, 0x0216, 0x021A, 0x021E: Channel [A
—
D] Egress Provisioning Register (R/W)
Reset default of registers = 0x361F.
Address
(Hex)
0211, 0215,
0219, 021D
Bit #
Name
Function
Reset
Default
00
15
—
14
—
Reserved.
These bits must be written to their
reset default value (00).
Ingress Watermark High for Channel
[A
—
D].
Defines threshold before which over-
flow is detected causing a head of FIFO dis-
card; data in the receive FIFO will be discarded
down to the next start of packet/cell.
Reserved.
These bits must be written to their
reset default value (00).
Ingress Watermark Low for Channel [A
—
D].
Defines how many words must be stored in the
ingress FIFO before transmission out of the
UTOPIA port, if an end of packet is not
received.
13
—
8
INGRESS_WATERMARK
_HIGH_[A
—
D][6:0]
110110
7
—
6
—
00
5
—
0
INGRESS_WATERMARK
_LOW_[A
—
D][6:0]
011111
Address
(Hex)
0212, 0216,
021A, 021E
Bit #
Name
Function
Reset
Default
00
15
—
14
—
Reserved.
These bits must be written to their
reset default value (00).
Egress Watermark High for Channel [A
—
D].
Defines how many words can be stored into the
egress FIFO before backpressure is applied to
the UTOPIA PHY Tx port to stop acceptance of
more traffic. Default value is set for packet
transfer. For ATM transfer, the value should be
configured as 0x29. For packet mode, this value
depends upon the specific user-interface char-
acteristics. The default value (110110) will work
for packet mode.
Reserved.
These bits must be written to their
reset default value (00).
Egress Watermark Low for Channel [A
—
D].
Defines how many words must be stored in the
egress FIFO before transmission to the data
engine, if an end of packet is not received.
13
—
8
EGRESS_WATERMARK_
HIGH_[A
—
D][6:0]
110110
7
—
6
—
00
5
—
0
EGRESS_WATERMARK_
LOW_[A
—
D][6:0]
011111