78Q2120C09-DB Maxim Integrated Products, 78Q2120C09-DB Datasheet - Page 8

• Manufacturer Part Number: 78Q2120C09-DB
• Description: BOARD DEMO 787Q2120C
• Manufacturer: Maxim Integrated Products

Specifications of 78Q2120C09-DB

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

CONTROL AND STATUS (CONTINUED)
MDI (MEDIA DEPENDENT INTERFACE)
Page: 8 of 35
ISO
ISODEF
ANEGA
TECH[2:0]
RPTR
TXOP/N
RXIP/N
NAME
NAME
44-46
61,62
52,51
PIN
PIN
47
50
2
1
TYPE
CID
TYPE
CI
CI
CI
CI
A
A
DESCRIPTION
ISOLATE: When set to logic one, the 78Q2120C will present a high
impedance on its MII output pins.
attached to the same MII interface. When the 78Q2120C is isolated, it still
responds to management transactions. This high impedance state can also
be achieved using the ISO bit in the MII register (MR0.10).
ISOLATE DEFAULT: This pin determines the power-up/reset default of the
ISO bit (MR0.10). If it is connected to VCC, the ISO bit will have a default
value of ‘1’. Otherwise, the bit defaults to ‘0’. When this signal is tied to VCC,
it allows multiple chips to be connected to the same MII interface.
AUTO-NEGOTIATION ABILITY: Connect to logic high to enable the auto-
negotiation function. When connected to logic low, the auto-negotiation logic
is disabled and manual technology selection is done through TECH[2:0] pins.
This pin is reflected as the ANEGA bit in 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. In 10BASE-T mode, the SQE test function is disabled. This mode can
also be enabled by setting bit MR16.15
DESCRIPTION
TRANSMIT OUTPUT POSITIVE/NEGATIVE: Transmitter differential outputs
for both 10BASE-T and 100BASE-TX operation.
RECEIVE INPUT POSITIVE/NEGATIVE:
both 10BASE-T and 100BASE-TX operation.
111
000
001
010
011
100
101
110
©
2009 Teridian Semiconductor Corporation
Technology Ability
Both 10BASE-T and 100BASE-TX, and
Both half and full duplex
None
10BASE-T, half duplex
100BASE-TX, half duplex
Both 10BASE-T and 100BASE-TX, half duplex only
None
10BASE-T Both half and full duplex
100BASE-TX Both half and full duplex
This allows for multiple chips to be
Receiver differential inputs for
10/100BASE-TX
Transceiver
78Q2120C
Rev 1.3