DS92UT16TUF Datasheet, PDF (9/86 Pages) National Semiconductor (TI) – UTOPIA-LVDS Bridge for 1.6 Gbps Bi-directional Data Transfers

6.0 Functional Description (Continued)
TC0
Flow Control 3
Flow Control 2
TC7
Flow Control 3
Flow Control 2
TC14
Flow Control 3
Flow Control 2
TC21
Flow Control 3
Flow Control 2
TC28
Flow Control 3
Flow Control 2
TC35
Flow Control 3
Flow Control 2
TC42
Flow Control 3
Flow Control 2
TC49
Flow Control 3
Flow Control 2
TABLE 4. F Channel Byte Usage Within the Frame
TC1
Flow Control 1
Flow Control 0
TC8
Flow Control 1
Flow Control 0
TC15
Flow Control 1
Flow Control 0
TC22
Flow Control 1
Flow Control 0
TC29
Flow Control 1
Flow Control 0
TC36
Flow Control 1
Flow Control 0
TC43
Flow Control 1
Flow Control 0
TC50
Flow Control 1
Flow Control 0
TC2
Flow Control 3
Flow Control 2
TC9
Flow Control 3
Flow Control 2
TC16
Flow Control 3
Flow Control 2
TC23
Flow Control 3
Flow Control 2
TC30
Flow Control 3
Flow Control 2
TC37
Flow Control 3
Flow Control 2
TC44
Flow Control 3
Flow Control 2
TC51
Flow Control 3
Flow Control 2
TC3
Flow Control 1
Flow Control 0
TC10
Flow Control 1
Flow Control 0
TC17
Flow Control 1
Flow Control 0
TC24
Flow Control 1
Flow Control 0
TC31
Flow Control 1
Flow Control 0
TC38
Flow Control 1
Flow Control 0
TC45
Flow Control 1
Flow Control 0
TC52
Flow Control 1
Flow Control 0
TC4
Flow Control 3
Flow Control 2
TC11
Flow Control 3
Flow Control 2
TC18
Flow Control 3
Flow Control 2
TC25
Flow Control 3
Flow Control 2
TC32
Flow Control 3
Flow Control 2
TC39
Flow Control 3
Flow Control 2
TC46
Flow Control 3
Flow Control 2
TC53
Flow Control 3
Flow Control 2
TC5
Flow Control 1
Flow Control 0
TC12
Flow Control 1
Flow Control 0
TC19
Flow Control 1
Flow Control 0
TC26
Flow Control 1
Flow Control 0
TC33
Flow Control 1
Flow Control 0
TC40
Flow Control 1
Flow Control 0
TC47
Flow Control 1
Flow Control 0
TC54
Flow Control 1
Flow Control 0
TC6
Alarm/Sig.
Link Labels
TC13
ECC1
ECC2
TC20
ECC3
ECC4
TC27
BIP16
TC34
Reserved
TC41
ECC5
ECC6
TC48
ECC7
ECC8
TC55
BIP16
6.3.7 OAM Channel
6.3.7.1 Remote Alarm and Signaling Byte
A byte-wide remote alarm and signaling channel is carried in
the F1 byte in TC6 as shown in Section 6.3.6 F Channel Byte
Usage Within the Frame. This provides a means for the
device at the far end of the LVDS link to signal an alarm
condition to the near end and vise-versa. This byte also
contains the ECC flow control signals. The format of this byte
is as shown below. Bit [0] is reserved.
TABLE 5. Remote Alarm and Signalling Byte
Bit
7
6
5
4
3
2
1
0
Function RLOSA RLOSB RBA RDSLL EVN ESSA ESSB Res
• RLOSA Remote Loss Of Signal lock at far end device
receive port A.
• RLOSB Remote Loss Of Signal lock at far end device
receive port B.
• RBA
Remote far end device active receive port. Set =
remote receive port B active and Clear = remote
receive port A active.
• RDSLL Remote far end device active port Descrambler
Loss of Lock. Set = Out of lock and Clear = In
lock.
• EVN ECC Tx Data Valid/Null indication.
• ESSA ECC RxA Stop/Start indication.
• ESSB ECC RxB Stop/Send indication.
The status of the received RLOSA, RLOSB, RBA and
RDSSL bits is reflected in the RARA register for receive port
A and in RBRA for receive port B. See Section 18.33 RE-
CEIVE PORT A REMOTE STATUS AND ALARMS — 0x3C
RARA and Section 18.52 RECEIVE PORT B REMOTE STA-
TUS AND ALARMS — 0x7C RBRA for descriptions of these
registers.
The function of the ECC signaling bits EVN, ESSA, and
ESSB is described in Section 16.0 Embedded Communica-
tion Channel Operation.
6.3.7.2 Link Trace Label Byte
Also, in TC6 a byte-wide link trace label is carried in the F2
byte as shown in Section 6.3.6 F Channel Byte Usage Within
the Frame. This allows the user to verify link connectivity,
which is especially useful when a number of cable links are
being used. The DS92UT16 may be programmed with both
a link label value to transmit and an expected link label.
Should the received link label not match the expected value,
an alarm interrupt may be raised.
The received Link Label byte is software accessible and an
interrupt may be raised on a change of received Link Label
byte. So the Link Label byte may also be used as a user
defined channel to pass one byte per frame across the link.
6.3.7.3 Embedded Communications Channel (ECC)
An Embedded Communications Channel is provided over
the link for software messaging, download, etc. in the F1/F2
bytes of TCs 13, 20, 41 and 48 as shown in Table 4. The
ECC byte contents are not processed by the DS92UT16.
Hence the DS92UT16 is transparent to and does not restrict
the system messaging protocol.
The ECC consists of an 8 byte Tx Buffer with corresponding
Tx Buffer Ready and Tx Buffer Send flags, and an 8 byte Rx
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