
XRT86SH328
PRELIMINARY
52
28-CHANNEL DS1/E1 FRAMER/LIU WITH DS3 MUX & VT-MAPPER - SONET APPLICATIONS
REV. P1.0.6
These four READ/WRITE bits-fields are used to configure the XRT86SH328 to operate in a variety of loop-back modes,
as is tabulated below.
BIT [7:0] - Transmit STS-1/STS-3 Telecom Bus - Sync Delay - Upper Byte
The Transmit STS-1/STS-3 Telecom Bus can be configured to alignment its transmission of SONET/SDH frames with
8kHz pulses being applied to the TxSBFP_IN_OUT input pin.
The user is expected to apply a pulse (with the period of either a 6.48MHz or a 19.44MHz clock signal) at a rate of 8kHz
to the TxSBFP_IN_OUT input (pin number P5). The Transmit STS-1/STS-3 Telecom Bus will align its transmission of
the very first byte of a new STS-1/STS-3 frame, with a pulse at this input pin.
These READ/WRITE bit-fields (along with that within the STS-1/STS-3 Telecom Bus Control Register - Byte 2) are used
to specify the amount of delay (in terms of either 6.48MHz or 19.44MHz clock periods) that will exist between the rising
edge of TxSBFP_IN_OUT and the transmission of the very first byte, within a given STS-1/STS-3 frame via the Transmit
STS-1/STS-3 Telecom Bus.
`
0x0000 - Configures each of the Transmit STS-1/STS-3 Telecom Bus Interfaces to transmit the very first byte of a
new STS-1/STS-3 frame, upon detection of the rising edge of the TxSBFP_IN_OUT.
`
0x0001 - Configures each of the Transmit STS-1/STS-3 Telecom Bus Interfaces to delay its transmission of the very
first byte of a new STS-1/STS-3 frame, by one 6.48MHz or 19.44MHz clock period, and so on.
N
OTE
:
This register is only active if the STS-1/STS-3 Telecom Bus Interface is enabled.
Loop Back Modes
L
OOP
-
BACK
[3:0]
R
ESULTING
L
OOP
-
BACK
M
ODE
0000
Normal Mode (e.g., No Loop-back Mode)
0001
Remote Line Loop-back
In this mode, all data that is received by the Receive STS-1/STS-3 Serial Interface will
be routed to the Transmit STS-1/STS-3 Serial Interface.
0010
Local Transport Loop-back
In this mode, all data that is being output via the Transmit STS-1/STS-3 TOH Processor
block will also be routed to the Receive STS-1/STS-3 TOH Processor block.
0011
Local Path Loop-back
In this mode, all data that is output by the Transmit STS-1/STS-3 POH Processor block
(e.g., towards the Transmit STS-1/STS-3 TOH Processor block) will be routed to the
Receive STS-1/STS-3 POH Processor block.
0100 - 1111
Reserved - Do Not Use
T
ABLE
40: STS-1/STS-3 T
ELECOM
B
US
C
ONTROL
R
EGISTER
- B
YTE
3 (A
DDRESS
= 0
X
0034)
BIT7
BIT6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
HRSYNC_Delay[15:8]
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
0
T
ABLE
41: STS-1/STS-3 T
ELECOM
B
US
C
ONTROL
R
EGISTER
- B
YTE
2 (A
DDRESS
= 0
X
0035)
BIT7
BIT6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
HRSYNC_Delay[7:0]
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
0