78Q2120C09-DB Maxim Integrated Products, 78Q2120C09-DB Datasheet - Page 12

• 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

MR0: Control Register (continued)
MR1: Status Register
Bits 1.15 through 1.11 reflect the ability of the 78Q2120C as configured by the TECH[2:0] pins. They do not
reflect any ability changes made via the MII Management interface to bits 0.13 (SPEEDSL) , 0.12 (ANEGEN) and
0.8 (DUPLEX).
Page: 12 of 35
0.6:0
1.15
1.14
1.13
1.12
1.11
1.10
BIT
BIT
0.8
0.7
SYMBOL TYPE
SYMBOL TYPE
DUPLEX
100T2_F
100X_H
100X_F
10T_H
100T4
10T_F
RSVD
COLT
R/W
R/W
R
R
R
R
R
R
R
DEFAULT DESCRIPTION
DEFAULT DESCRIPTION
(1)
(1)
(1)
(1)
(1)
0
0
0
0
©
2009 Teridian Semiconductor Corporation
Duplex Mode: This bit determines whether the device supports full-
duplex or half-duplex. A ‘1’ indicates full-duplex operation and a ‘0’
indicates half-duplex. This bit will default to ‘0’ upon reset and will
be writeable if the TECH[2:0] pins are all logic zero and auto-
negotiation is not enabled. If auto-negotiation is not enabled and
the TECH[2:0] pins are set to indicate that only full-duplex is
supported, this bit will be forced to ‘1’ and will not be writeable. If
auto-negotiation is not enabled and the TECH[2:0] pins are set to
indicate that only half-duplex is supported, this bit will be forced to
‘0’ and will not be writeable. When auto-negotiation is enabled, this
bit will not be writeable and will have no effect on the device. If the
TECH[2:0] pins are brought to zero from another value, this bit will
retain its original value until it is overwritten.
Collision Test: When this bit is set to ‘1’, the device will assert the
COL signal in response to the assertion of the TX_EN signal.
Collision test is disabled if the PCSBP pin is high. Collision test can
be activated regardless of the duplex mode of operation.
Reserved
100BASE-T4 Ability: Reads ‘0’ to indicate the 78Q2120C does not
support 100Base-T4 mode.
100BASE-TX Full Duplex Ability:
100BASE-TX Half Duplex Ability:
10BASE-T Full Duplex Ability:
10BASE-T Half Duplex Ability:
100BASE-T2 Full Duplex Ability:
78Q2120C does not support 100Base-T2 full duplex mode.
0 : Not able
1 : Able
0 : Not able
1 : Able
0 : Not able
1 : Able
0 : Not able
1 : Able
Reads ‘0’ to indicate the
10/100BASE-TX
Transceiver
78Q2120C
Rev 1.3