LAN83C183 Datasheet, PDF (15/113 Pages) SMSC Corporation – FAST ETHERNET PHYSICAL LAYER DEVICE

to an external Ethernet controller. The format of the received data at the Controller
interface is as shown in Table 1.2.
Table 1.2 Receive Preamble and SFD Bits at MAC Nibble Interface
Signals
Bit Value
RXDO X 1¹ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1² 1 D0³ D4⁴
RXD1 X 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 D1 D5
RXD2 X 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 D2 D6
RXD3 X 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 D3 D7
RX_DV 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1. First preamble nibble received. Depending on the mode, the device may eliminate either all or some
of the preamble nibbles, up to the first SFD nibble.
2. First SFD nibble received.
3. First data nibble received.
4. D0 through D7 are the first 8 bits of the data field.
1.1.2.2 100BASE-FX
100BASE-FX operation is similar to 100BASE-TX operation except:
• The transmit output/receive input is not scrambled or MLT3 encoded
• The transmit data is output to a FX transmitter instead of the TP waveshaper/
transmitter
• The receive data is input to the FX ECL level detector instead of the equalizer
and associated TP circuitry
• The FX Interface has a signal detect input
1.1.2.3 10BASE-T
10BASE-T operation is similar to the 100BASE-TX operation except:
• There is no scrambler/descrambler
• The encoder/decoder is Manchester instead of 4B5B
• The data rate is 10 Mbits/s instead of 100 Mbits/s,
• The twisted-pair symbol data is two-level Manchester instead of ternary MLT-3.
• The transmitter generates link pulses during the idle period
• The transmitter detects the jabber condition
• The receiver detects link pulses and implements the AutoNegotiation algorithm
SMSC DS – LAN83C183
15
Rev. 12/14/2000