DS92UT16TUF Datasheet, PDF (32/86 Pages) National Semiconductor (TI) – UTOPIA-LVDS Bridge for 1.6 Gbps Bi-directional Data Transfers

16.0 Embedded Communication Channel Operation (Continued)
20031615
FIGURE 16. ECC Transmit Flow Chart
20031616
FIGURE 17. ECC Receive Flow Chart (Port A)
16.2 ECC OPERATION WITH ACTIVE AND STANDBY
RECEIVERS
The DS92UT16 has two independent receive sections, Port
A and Port B. These each contain an ECC receive section
and the ECC can be configured to receive over Port A or Port
B or over both Port A and Port B together. The ECC receive
port can be selected independent of the traffic receive port.
Therefore, traffic data is received on the active port desig-
nated by the LBA bit of the LKSC register but the ECC can
receive on either Port A or Port B as designated by the
ECCA and ECCB bits of the same LKSC register. In a
protected system with an active and standby LVDS link this
can be used to communicate with the standby link while
traffic continues to be received from the active link. Figure 18
shows three DS92UT16 devices with ECC communication
over both links.
ECC Receive on Port A: Device 1 communicating with
Device 2 only.
Device 1: For the ECC to communicate across Link A only,
the ECCA bit of the LKSC register is set and the ECCB bit is
clear. The incoming valid ESS signal received over Link A,
“RxA valid ESS”, is the only one used by the ECC transmit
section in Tx. The RxA port is programmed to extract the
incoming ESSA bit as the valid ESS, as the Device 1 trans-
mitter is connected to Device 2 receiver Port A. This is
accomplished by clearing the RAESS bit of the RACTL
register.
In this case, when an ECC message is transmitted, the “RxA
valid ESS” signals when the message has been successfully
received by the far-end Device 2. So, ECC communications
only occur over Link A between Device 1 and Device 2.
Device 2: The ECCA bit of the LKSC register is set and the
ECCB bit is clear. The incoming valid ESS signal received
over Link A, “RxA valid ESS”, is the only one used by the
ECC transmit section in Tx. The RxA port is programmed to
extract the incoming ESSA bit as the valid ESS, as the
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