78Q2120-64CG ETC [List of Unclassifed Manufacturers], 78Q2120-64CG Datasheet - Page 8

• Manufacturer Part Number: 78Q2120-64CG
• Description: 10/100BASE-TX Ethernet Transceiver
• Manufacturer: ETC [List of Unclassifed Manufacturers]

78Q2120
10/100BASE-TX
Ethernet Transceiver
CONTROL AND STATUS
MDI (MEDIA DEPENDENT INTERFACE)
LED INDICATORS
The LED pins use standard logic drivers. They output a logic low when the LED is meant to be on and a logic high when it is
meant to be off. The LED should be connected in series with a resistor between the output pin and the power supply.
PIN
ANEGA
TECH[2:0]
RPTR
TXOP,
TXON
RXIP,
RXIN
LEDL
LEDTX
LEDRX
LEDCOL
LEDBTX
LEDBT
LEDFDX
64-PIN
61, 62
52, 51
44-46
40
39
38
37
36
48
49
47
50
80-PIN
77,78
64,63
53-55
48
47
46
45
44
57
58
(continued)
56
61
TYPE
A
A
O
O
O
O
O
O
O
I
I
I
DESCRIPTION
AUTO-NEGOTIATION ABILITY: Strapped to logic high to allow auto-
negotiation function. When strapped to logic low, auto-negotiation
logic is disabled and manual technology selection is done through
TECH[2:0]. This pin is reflected as ANEGA bit (MR1.3).
TECHNOLOGY ABILITY/SELECT: TECH[2:0] sets the technology ability of the
chip which is reflected in MR0.13,8 MR1.14:11 and MR4.12:5.
TECH[2:0]
REPEATER MODE: When pulled high, this pin puts the chip into repeater
mode. In this mode, full duplex is prohibited, CRS responds to receive
activity only and, in 10BASE-T mode, the SQE test function is disabled. This
mode can also be entered with MR16.15.
TRANSMIT OUTPUT POSITIVE/NEGATIVE: Transmitter outputs for
both 10BASE-T and 100BASE-TX.
RECEIVE INPUT POSITIVE/NEGATIVE: Receiver inputs for both
10BASE-T and 100BASE-TX.
LED LINK: ON for link up.
LED TRANSMIT: ON when there is a transmission (normally OFF).
LED RECEIVE: ON when there is a reception (normally OFF).
LED COLLISION: In half duplex mode, this is a collision indicator and turns-
ON when a collision occurs. In full duplex mode, this LED is held OFF.
LED 100BASE-TX: ON for 100BASE-TX connection and OFF for
other connections. LEDBTX is OFF during auto-negotiation.
LED 10BASE-T: ON for 10BASE-T connection and OFF for other
connections. LEDBT is OFF during auto-negotiation.
LED FULL DUPLEX: ON when in full duplex mode and OFF when in
half duplex mode.
000
111
001
010
011
100
101
110
8
Advertise no technology capability; however,
parallel detect from the link partner will
establish the link speed.
Both 10BASE-T and 100BASE-TX,
Both half and full duplex
10BASE-T, half duplex
100BASE-TX, half duplex
Both 10BASE-T and 100BASE-TX,half duplex
None
10BASE-T Both half and full duplex
Technology ability
100BASE-TX Both half and full duplex