SLK2701 Datasheet, PDF (7/21 Pages) Texas Instruments – OC-48/24/12/3 SONET/SDH MULTIRATE TRANSCEIVER

SLK2701
OCĆ48/24/12/3 SONET/SDH MULTIRATE TRANSCEIVER
SLLS518 − DECEMBER 2001
detailed description
The SLK2701 device is designed to support the OC-48/24/12/3 data rates. It also supports a higher data rate
that may be required for FEC support, up to 2.7 Gbps. The operating data speed can be configured through the
RSEL0 and RSEL1 pins as indicated in Table 1 for normal SONET rates. For FEC support, the clock and data
rates need to be scaled up as required. The highest data and clock rates supported are 675 Mbps and 675 MHz,
respectively.
Table 1. Data Rate Select
SERIAL DATA RATE
OC-48: 2.488 Gbps
OC-24: 1.244 Gbps
OC-12: 622 Mbps
OC-3: 155.52 Mbps
RSEL0
0
1
0
1
RSEL1
0
0
1
1
PARALLEL LVDS DATA RATE
622.08 Mbps
311.04 Mbps
155.52 Mbps
38.88 Mbps
TXCLK/RXCLK
622.08 MHz
311.04 MHz
155.52 MHz
38.88 MHz
The user can also enable the autorate detection circuitry through the AUTO_DETECT pin. The device
automatically detects the OC-N of the data line rate and generates two bits of output to indicate the data rate
to other devices in the system. When using AUTO_DETECT, RSEL0 and RSEL1 need to be set to 00 or be
unconnected.
Table 2. Data Rate Reporting Under Autorate Detection Mode
SERIAL DATA RATE
OC-48: 2.488 Gbps
OC-24: 1.244 Gbps
OC-12: 622 Mbps
OC-3: 155.52 Mbps
RATEOUT0
0
1
0
1
RATEOUT1
0
0
1
1
PARALLEL LVDS DATA RATE
622.08 Mbps
311.04 Mbps
155.52 Mbps
38.88 Mbps
TXCLK/RXCLK
622.08 MHz
311.04 MHz
155.52 MHz
38.88 MHz
The SLK2701 device has four operational modes controlled by two configuration pins. Table 3 lists these
operational modes. When the device is put in a certain mode, unused circuit blocks are powered down to
conserve system power.
While the transceiver mode, transmit only mode, and receive only mode are straightforward, the repeater mode
of operation is shown in Figure 5. The receive serial data is recovered by the extracted clock, and it is then sent
back out on the transmit serial outputs. The data eye is open both vertically and horizontally in this process. In
the repeater mode, the user can select to turn on the RX demultiplexer function through RX_MONITOR pin and
allow the parallel data to be presented. This feature enables the repeater device not only to repeat but also to
listen in.
Table 3. Operational Modes
MODE
1
2
3
4
CONFIG0
0
0
1
1
CONFIG1
0
1
0
1
DESCRIPTION
Full duplex transceiver mode
Transmit only mode
Receive only mode
Repeater mode
high-speed electrical interface
The high-speed serial I/O uses a PECL-compatible interface. The line could be directly coupled or ac-coupled.
Refer to Figures 10 and 11 for configuration details. As shown in the figures, an on-chip 100-Ω termination
resistor is placed differentially at the receive end.
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
7