78Q2120 Teridian Semiconductor Corp. (TDK Semiconductor), 78Q2120 Datasheet - Page 8

• Manufacturer Part Number: 78Q2120
• Description: 10/100 Ethernet PHYS
• Manufacturer: Teridian Semiconductor Corp. (TDK Semiconductor)

CONTROL AND STATUS
NAME
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.
NAME
NAME
ANEGA
TECH[2:0]
RPTR
TXOP,
TXON
RXIP,
RXIN
LEDL
LEDTX
LEDRX
LEDCOL
LEDBTX
LEDBT
LEDFDX
44-46
PIN
PIN
PIN
47
50
61,
52,
62
51
40
39
38
37
36
48
49
(continued)
TYPE
TYPE
TYPE
I
I
I
O
O
O
O
O
O
O
A
A
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
DESCRIPTION
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.
DESCRIPTION
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.
111
001
010
011
100
101
110
8
Technology ability
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
100BASE-TX Both half and full duplex
Ethernet Transceiver
10/100BASE-TX