TLK3118 Datasheet, PDF (12/57 Pages) Texas Instruments – Redundant XAUI Transceiver

TLK3118
Redundant XAUI Transceiver
SLLS628A – DECEMBER 2004 – REVISED APRIL 2005
www.ti.com
XAUI
RDP/N0 ... D D D D A
RDP/N1 ... D D D T A
RDP/N2 ... D D D K A
RDP/N3 ... D D D K A
Running Disparity Error
Detected by /A/ Yields
Running Disparity Error
Detected by /T/ Yields
Running Disparity Error
Detected by /K/ Yields
Running Disparity Error
Detected by /K/ Yields
XGMII
... D D D E I
... D D E T I
... D D E I I
... D D E I I
D = Data, T = K29.7, A = K28.3, K = K28.5, E = Error (0xFE), I = Idle
Figure 11. End-of-Packet Error Detection
Fault Detection and Reporting
The TLK3118 will detect and report local faults as well as forward both local and remote faults as defined in the
IEEE P802.3ae 10Gbps Ethernet Standard to aid in fault diagnosis. All faults detected by the TLK3118 are
reported as local faults to the upper layer protocols. Once a local fault is detected in the TLK3118, MDIO register
bit 4:5.1.7 is set. Fault sequences, sequence ordered sets received by the TLK3118, either on the Transmit Data
Bus or on the high speed receiver pins, are forwarded without change to the MDIO registers in the TLK3118.
Also, note that the TLK3118 is capable of performing CTC operation where only RF and LF or any Q sequences
are transported (not generated) in either the transmit or receive direction.
TLK3118 reports a fault by outputting a K28.4 (0x9C) on RXD(7:0), 0x00 on RXD(15:8) and RXD(23:8) and 0x01
for local faults on RXD(31:24). Forwarding of remote faults is handled as a normal transmission. Note that the
TLK3118 will not generate a remote fault indication or any other type of Q.
Receive Synchronization and Skew Compensation
Regardless of which mode is selected, the TLK3118 has a FIFO enabled on the receive data path coming from
each serial link to compensate for channel skew and clock phase and frequency tolerance differences between
the recovered clocks for each channel and the receive output clock RCLK. This FIFO has a depth of 32 locations
(32 bits wide for each location).
The de-skew of the 4 serial links that make up each XAUI channel into a single 32 bit wide column of data is
accomplished by alignment of the receive FIFO’s on each serial link to a K28.3 control code sent during the
inter-packet gap (IPG) between data packets or during initial link synchronization. The K28.3 code (referred to as
the “A” or alignment code) is transmitted on the first column following the end of the data packet as shown in
Figure 13.
The column de-skew state machine is provided in the following figure. The status of column alignment can be
monitored by reading MDIO registers 4:5.24.12 for global alignment or 4:5.24.3:0 for particular channel
synchronization.
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