
PRELIMINARY
XRT86SH328
53
REV. P1.0.6
28-CHANNEL DS1/E1 FRAMER/LIU WITH DS3 MUX & VT-MAPPER - SONET APPLICATIONS
BIT [7:0] - Transmit STS-1/STS-3 Telecom Bus - Sync Delay - Lower Byte
The Transmit STS-1/STS-3 Telecom Bus is aligned 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 3) are used
to specify the amount of delay (in terms of either a 6.48MHz or a 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. S
`
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.
BIT 7 - Set Telecom Bus to STS-1/STS-3 Mode:
This READ/WRITE bit-field is used to configure the STS-1/STS-3 Telecom Bus Interface to operate at either the STS-
1/STS-3 or STS-3 rates.
`
.0 - Configures the Telecom Bus Interface to operate at the STS-3/STS-1/STS-3 rate. In this case, the Telecom Bus
Interface will operate at a rate of 19.44MHz.
`
1 - Configures the Telecom Bus Interface to operate at the STS-1/STS-3 rate. In this case, the Telecom Bus Interface
will operate with a clock rate of 6.48MHz.
N
OTE
:
This bit-field is only active if the XRT86SH328 has been configured to transmit/receive data (on the high-speed
side) via the Telecom Bus Interface.
BIT 6 - Fractional Bandwidth Enable:
If the XRT86SH328 is configured to transmit/receive data via the Telecom Bus Interface as STS-3/STS-1/STS-3 rates,
then this READ/WRITE bit-field can be used to configure the XRT86SH328 to operate in the Fractional Bandwidth
Mode.
If the XRT86SH328 is configured to operate in the Fractional Bandwidth Mode, then it will only fill in the STS-1/STS-3
time-slot data (within this outbound STS-3/STS-1 or STS-3 Data-stream) that pertains to this particular XRT86SH328.
The XRT86SH328 will tri-state the Transmit STS-1/STS-3 Telecom bus interface coincident to whenever the other STS-
1/STS-3 time-slot data would ordinarily be output via the STS-3/STS-1/STS-3 Telecom Bus Interface.
If the XRT86SH328 is NOT configured to operate in the Fractional Bandwidth Mode, then it will fill in the STS-1/STS-3
time-slot data (within this outbound STS-3/STS-1/STS-3 data-stream) that pertains to this particular XRT86SH328. The
XRT86SH328 will automatically set the bytes (within all of the remaining STS-1/STS-3 time-slots) to 0x00 as it outputs
this STS-3/STS-1/STS-3 data-stream via the Transmit STS-3/STS-1/STS-3 Telecom Bus Interface.
`
0 - Configures the XRT86SH328 to NOT operate in the Fractional Bandwidth Mode.
`
1 - Configures the XRT86SH328 to operate in the Fractional Bandwidth Mode.
N
OTES
:
1.
If the user wishes to design in three (3) XRT86SH328s (into his/her system) such that they are sharing
the same STS-3/STS-1/STS-3 Telecom Bus, then the user must set this bit-field to 1.
T
ABLE
42: STS-3/STS-1/STS-3 T
ELECOM
B
US
C
ONTROL
R
EGISTER
- B
YTE
1 (A
DDRESS
= 0
X
0036)
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
Set Telecom
Bus to STS-
1/STS-3
Mode
Fractional
Bandwidth
Enable
Slot_0
Master
Slot[1:0]
Telecom Bus
Parity
Include V1
Signal
Framing
Pulse Enable
Telecom Bus
- V1 Signal
Support
Enable
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
0