TLK2711JRZQE Datasheet, PDF (11/27 Pages) Texas Instruments – 1.6 TO 2.7 GBPS TRANSCEIVER

TLK2711
1.6 TO 2.7 GBPS TRANSCEIVER
SLLS501 – SEPTEMBER 2001
comma detect and 8-bit/10-bit decoding (continued)
Decoding provides two additional status signals, RKLSB and RKMSB. When RKLSB is asserted , an 8-bit/10-bit
K code was received and the specific K code is presented on the data bits RXD0–RXD7; otherwise, an
8-bit/10-bit D code was received. When RKMSB is asserted, an 8-bit/10-bit K code was received and the specific
K-code is presented on data bits RXD8–RXD15; otherwise, an 8-bit/10-bit D code was received (see Table 3).
The valid K codes the TLK2711 decodes are provided in Table 4. An error detected on either byte, including K
codes not in Table 4, causes that byte only to indicate a K0.0 code on the RK×SB and associated data pins,
where K0.0 is known to be an invalid 8-bit/10-bit code. A loss of input signal causes a K31.7 code to be presented
on both bytes, where K31.7 is also known to be an invalid 8-bit/10-bit code.
RKLSB
0
0
1
1
Table 3. Receive Status Signals
RKMSB
0
1
0
1
DECODED 20 BIT OUTPUT
Valid data on RXD(0–7), Valid data RXD(8–15)
Valid data on RXD(0–7), K code on RXD(8–15)
K code on RXD(0–7), Valid data on RXD(8–15)
K code on RXD(0–7), K code on RXD(8–15)
Table 4. Valid K Characters
K CHARACTER
RECEIVE DATA BUS
(RXD[7–0]) OR (RXD[15–8])
K28.0
K28.1^†
000 11100
001 11100
K28.2
010 11100
K28.3
011 11100
K28.4
K28.5^†
100 11100
101 11100
K28.6
K28.7^†
110 11100
111 11100
K23.7
111 10111
K27.7
111 11011
K29.7
111 11101
K30.7
111 11110
† _{Should only be present on RXD[7–0] when in running disparity < 0.}
power down mode
When the ENABLE pin is pulled low, the TLK2711 goes into power-down mode. In the power-down mode, the
serial transmit pins (TXN), the receive data bus pins (RXD[0:15]), and RKLSB goes into a high-impedance
state. In the power-down condition, the signal detection circuit draws less than 15 mW. When the TLK2711 is
in the power-down mode, the clock signal on the TXCLK terminal must be provided.
loss of signal detection
The TLK2711 has a loss of signal detection circuit for conditions where the incoming signal no longer has a
sufficient voltage level to keep the clock recovery circuit in lock. The signal detection circuit is intended to be
an indication of gross signal error conditions, such as a detached cable or no signal being transmitted, and not
an indication of signal coding health. The TLK2711 reports this condition by asserting RKLSB, RKMSB and
RXD[0:15] terminals to a high state. As long as the differential signal is above 200 mV in differential magnitude,
the LOS circuit does not signal an error condition.
PRBS verification
The TLK2711 also has a built-in BERT function in the receiver side that is enabled by the PRBSEN. It can check
for errors and report the errors by forcing the RKLSB terminal low.
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
11