EP82562ET Datasheet, PDF (17/40 Pages) Intel Corporation – 10/100 Mbps Platform LAN Connect (PLC)

Networking Silicon — 82562ET
4.2.2
4.2.2.1
4.2.2.2
10BASE-T Receive Blocks
10BASE-T Manchester Decoder
The 82562ET performs Manchester decoding and timing recovery in 10BASE-T mode. The
Manchester encoded data stream is decoded from the receive differential pair. This data is
transferred to the controller at 2.5 MHz/nibble. The high-performance circuitry of the 82562ET
exceeds the IEEE 802.3 jitter requirements.
10BASE-T Twisted Pair Ethernet (TPE) Receive Buffer and Filter
In 10 Mbps mode, data is expected to be received on the receive differential pair after passing
through isolation transformers. The filter is implemented inside the 82562ET for supporting single
magnetics that are shared with the 100BASE-TX side. The input differential voltage range for the
Twisted Pair Ethernet (TPE) receiver is greater than 585 mV and less than 3.1 V. The TPE receive
buffer distinguishes valid receive data, link test pulses, and the idle condition, according to the
requirements of the 10BASE-T standard.
The following line activity is determined to be inactive and is rejected as invalid data:
• Differential pulses of peak magnitude less than 300 mV.
• Continuous sinusoids with a differential amplitude less than 6.2 V_PP and frequency less than 2
MHz.
• Sine waves of a single cycle duration starting with 0° or 180° phase that have a differential
amplitude less than 6.2 V_PP and a frequency of at least 2 MHz and not more than 16 MHz.
These single-cycle sine waves are discarded only if they are preceded by 4 bit times (400 ns)
of silence.
All other activity is determined to be either data, link test pulses, Auto-Negotiation fast link pulses,
or the idle condition.
Datasheet
13