SLXT973QE Cortina Systems Inc, SLXT973QE Datasheet - Page 61

• Manufacturer Part Number: SLXT973QE
• Manufacturer: Cortina Systems Inc

Specifications of SLXT973QE

• Lead Free Status / RoHS Status: Not Compliant

LXT973 Transceiver
Datasheet
249426, Revision 6.0
13 July 2007
10.0
10.1
10.2
10.3
10.4
10.5
Cortina Systems
10 Mbps Operation
The LXT973 Transceiver operates as a standard 10 Mbps transceiver. Data transmitted
by the MAC as a 4-bit nibble is serialized, Manchester-encoded, and transmitted on the
twisted-pair outputs
(DPAP/N_0 and DPBP/N_1). Received data is decoded, de-serialized into 4-bit nibbles,
and passed on RXD[3:0] to the MAC across the MII. The LXT973 Transceiver supports all
the standard 10 Mbps functions.
Link Test
In 10 Mbps mode, the LXT973 Transceiver always transmits link pulses. If the Link Test
Function is enabled, it monitors the connection for link pulses. Once it detects two to
seven link pulses, data transmission is enabled and remains enabled as long as the link
pulses or data reception continues. If the link pulses stop, the data transmission is
disabled.
If the Link Test function is disabled, the LXT973 Transceiver may transmit packets
regardless of detected link pulses. The Link Test function can be disabled by setting Port
Configuration Register bit 16.14.
10Base-T Link Failure Criteria and Override
Link failure occurs if Link Test is enabled and link pulses stop being received. If this
condition occurs, the LXT973 Transceiver returns to the auto-negotiation phase if auto-
negotiation is enabled. If the Link Integrity Test function is disabled by setting the Port
Configuration Register bit 16.14, the LXT973 Transceiver transmits packets, regardless of
link status.
SQE (Heartbeat)
By default, the SQE (heartbeat) function is disabled on the LXT973 Transceiver. To
enable this function, set Register bit 16.9 = 1. When this function is enabled, the LXT973
Transceiver asserts its COL output for
5 - 15 bit times after each packet. See
Jabber
If the MAC begins a transmission that exceeds the jabber timer, the LXT973 Transceiver
disables the transmit and loopback functions and enables the COL pin. The LXT973
Transceiver automatically exits jabber mode after 250 - 750 ms. This function can be
disabled by setting Register bit 16.10 = 1. See
parameters.
Polarity Correction
The LXT973 Transceiver automatically detects and corrects for the condition where the
receive signal (DPBP/N_0 and DPAP/N_1) is inverted. Reversed polarity is detected if 8
inverted link pulses, or 4 inverted end-of-frame markers, are received consecutively. If link
pulses or data are not received for 96-130 ms, the polarity state is reset to a non-inverted
state.
®
LXT973 10/100 Mbps Dual-Port Fast Ethernet PHY Transceiver
Figure 35 on page 87
Figure 36 on page 87
for SQE timing parameters.
10.0 10 Mbps Operation
for jabber timing
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