Datasheet

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SLLS427D − AUGUST 2000 − REVISED JULY 2003
6
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Terminal Functions (Continued)
TERMINAL
TYPE
DESCRIPTION
NAME NO.
TYPE
DESCRIPTION
RX_CLK 41 O
†
Recovered clock. Output clock that is synchronized to RXD, RX_ER, RX_DV/LOS. RX_CLK is
the recovered serial data rate clock divided by 20. RX_CLK is held low during power-on reset.
RX_ER/
PRBS_PASS
29 O
‡
Receive error. When RX_ER and RX_DV/LOS are asserted, indicates that an error was
detected somewhere in the frame presently being output on the receive data bus. When RX_ER
is asserted and RX_DV/LOS is deasserted, indicates that carrier extension data is being
presented (see Table 2). The RX_ER is in high-impedance state during power-on reset.
When PRBSEN= low (deasserted), this terminal is used to indicate receive error (RX_ER).
When PRBSEN = high (asserted), this terminal indicates status of the PRBS test results
(High=pass).
RX_DV/
LOS
30 O
‡
Receive data valid. RX_DV/LOS is output by the transceiver to indicate that valid recovered and
decoded data is being output on the receive data bus. RX_DV/LOS is asserted high continuously
from the first recovered word of the frame through the final recovered word and is negated prior
to the first rising edge of RX_CLK that follows the final word (see Table 2). The RX_DV/LOS is
in high-impedance state during power-on reset.
If, during normal operation, the differential signal amplitude on the serial receive terminals is
below 200 mV, RX_DV/LOS is asserted high along with RX_ER and the receive data bus to
indicate a loss of signal condition. If the device is in power-down mode, RX_DV/LOS is the output
of the signal detect circuit and is asserted low when a loss of signal condition is detected.
TESTEN 27 I Test mode enable. This terminal should be left unconnected or tied low.
TXD0
TXD1
TXD2
TXD3
TXD4
TXD5
TXD6
TXD7
TXD8
TXD9
TXD10
TXD11
TXD12
TXD13
TXD14
TXD15
62
63
64
2
3
4
6
7
10
11
12
14
15
16
17
19
I
§
Transmit data bus. These inputs carry the 16-bit parallel data output from a protocol device to
the transceiver for encoding, serialization, and transmission. This 16-bit parallel data is clocked
into the transceiver on the rising edge of GTX_CLK as shown in Figure 10.
TX_EN 20 I
§
Transmit enable. TX_EN in combination with TX_ER indicates the protocol device is presenting
data on the transmit data bus for transmission. TX_EN must be high with the first word of the
preamble and remains asserted while all words to be transmitted are presented on the receive
data bus. TX_EN must be negated prior to the first rising edge of GTX_CLK following the final
word of a frame.
TX_ER 22 I
§
Transmit error coding. When TX_ER and TX_EN are high, indicates that the transceiver
generates an error somewhere in the frame presently being transferred. When TX_ER is
asserted and TX_EN is deasserted, indicates the protocol device is presenting carrier extension
data. When TX_ER is deasserted with TX_EN asserted, indicates that normal data is being
presented.
V
DD
1, 9,
23, 38,
48
Digital logic power. Provides power for all digital circuitry and digital I/O buffers.
V
DDA
55, 57 Analog power. V
DDA
provides a supply reference for the high-speed analog circuits, receiver and
transmitter
†
Low during power-on reset.
‡
High-impedance during power-on reset
§
Internal pulldown