SI5100-EVB Datasheet, PDF (6/48 Pages) Silicon Laboratories – Evaluation Board Set for Si5100 and Si5110 OC-48/STM-16 SONET/SDH TRANSCEIVERS

Si5100/Si5110-EVB
Line Loopback
When configured in line-loopback mode, the device
passes the received/recovered data and timing to the
transmitter. The transmitter buffers the data through the
FIFO and filters the jitter using the loop-bandwidth
selected by BWSEL[1:0]. Operation in line loopback
mode is depicted in Figure 5. Jumper settings for line
loopback mode are given in Tables 1, 3 (Si5100), and 4
(Si5110). This mode of operation is attainable with both
versions of the motherboard.
Full-Duplex
This mode is identical to normal operation of the device
in a system. TX and RX can be asynchronous (up to
±300 ppm) so all timing is independent. TXCLK16IN is
chosen as the transmitter CMU reference clock via the
REFSEL pin. Operation in full-duplex mode is depicted
in Figure 6. Jumper settings for full-duplex mode are
given in Tables 1, 3 (Si5100), and 4 (Si5110). If the
loopback motherboard is used, the full-duplex mode
effectively becomes an external loopback mode, and
RXCLK1 should be connected to TXCLK16IN/
TXCLK4IN to clock in the data.
Diagnostic Loopback (Parallel Side Loopback)
This mode passes the data present on the transmit
parallel inputs (TXDIN[15:0] for Si5100; TXDIN[3:0] for
Si5110) to the receive parallel data outputs
(RXDOUT[15:0] for Si5100; RXDOUT[3:0] for Si5110).
TXCLK16IN/TXCLK4IN is chosen as the transmitter
CMU reference clock via the REFSEL pin. Operation in
diagnostic loopback mode is depicted in Figure 7.
Jumper settings for diagnostic loopback mode are given
in Tables 2, 3 (Si5100), and 4 (Si5110). The full-duplex
motherboard is required for this mode.
RXDIN
TXDOUT
TXREFCLK
TXCLK
Si5100/Si5110
Receiver
Transmitter
Figure 6. Full Duplex
RXDOUT
RXCLK1
TXCLK16IN/
TXCLK4IN
TXDIN
RXDIN
TXDOUT
TXREFCLK
TXCLK
Si5100/Si5110
Receiver
Transmitter
RXDOUT
RXCLK1
TXCLK16IN/
TXCLK4IN
TXDIN
Figure 7. Diagnostic Loopback
RXDIN
TXDOUT
TXREFCLK
TXCLK
Si5100/Si5110
Receiver
Transmitter
RXDOUT
RXCLK1
TXCLK16IN/
TXCLK4IN
TXDIN
Figure 5. Line Loopback
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Preliminary Rev. 0.5