XRT91L32ES Exar, XRT91L32ES Datasheet - Page 28

• Manufacturer Part Number: XRT91L32ES
• Description: LIN Transceivers SONET SDH 8 bit TRANCEIVER
• Manufacturer: Exar

Specifications of XRT91L32ES

• Product Category: LIN Transceivers
• Rohs: yes

XRT91L32
STS-12/STM-4 OR STS-3/STM-1 SONET/SDH TRANSCEIVER
The serial remote loopback function is activated by setting RLOOPS "High". When serial remote loopback is
activated, the high-speed serial receive data from RXIP/N is presented at the high speed transmit output
TXOP/N, and the high-speed recovered clock is selected and presented to the high-speed transmit clock input
of the Retimer. During serial remote loopback, the high-speed receive data (RXIP/N) is also converted to
parallel data and presented at the low-speed receive parallel interface RXDO[7:0]. The recovered receive clock
is also divided by 8 and presented at the low-speed clock output RXPCLKO to synchronize the transfer of the
8-bit received parallel data. A simplified block diagram of serial remote loopback is shown in Figure 16.
F
The digital local loopback is activated when the DLOOP signal is set "High." When digital local loopback is
activated, the high-speed data from the output of the parallel to serial converter is looped back and presented
to the high-speed input of the receiver serial to parallel converter. The CMU output is also looped back to the
receive section and is used to synchronize the transfer of the data through the receiver. In Digital loopback
mode, the transmit data from the transmit parallel interface TXDI[7:0] is serialized and presented to the high-
speed transmit output TXOP/N using the high-speed 622.08/155.52 MHz transmit clock generated from the
clock multiplier unit and presented to the input of the Retimer and SIPO. A simplified block diagram of digital
loopback is shown in Figure 17. Receive Data mute upon LOS, as shown in Figure 7, applies to Digital Local
F
Loopback Mode
4.0 DIAGNOSTIC FEATURES
4.1
4.2
IGURE
IGURE
R x Parallel O utput
16. S
17. D
Serial Remote Loopback
Digital Local Loopback
Rx Parallel Output
Tx Parallel Input
ERIAL
IGITAL
R
L
EMOTE
OCAL
L
Serial Rem ote Loopback
L
OOPBACK
OOPBACK
Digital Loopback
PISO
SIPO
SIPO
PISO
26
Re-Timer
Re-Timer
CD R
CDR
Input Drivers
Output Drivers
O utput Drivers
Input Drivers
LVPECL
LVPECL
LVPECL
LVPECL
Tx Serial Output
Tx Serial O utput
Rx Serial Input
xr
REV. 1.0.3