
LAN8700 Evaluation Board User Manual
SMSC LAN8700
USER MANUAL
Revision 1.0 (02-23-10)
5
2.2.2
Boot Mode Configuration
The LAN8700 can be configured to boot into a specific mode of operation at power-up via the
MODE[2:0] configuration straps. By default, the MODE[2:0] configuration straps are pulled-up internally
to “1”. Unpopulated pull-down resistor pads are provided for each MODE[2:0] configuration strap.
These pull-down resistors should only be populated when the corresponding MODE[2:0] configuration
strap is desired to default to “0”. A list of the LAN8700 modes and their corresponding pull-down
resistor configurations are shown in
Note 2.1
Refer to the LAN8700 Datasheet for additional information on Repeater mode.
Note 2.2
Refer to the LAN8700 Datasheet for additional information on Power-Down mode.
Table 2.3 MODE[2:0] Resistor Configuration
MODE[2:0]
MODE DEFINITIONS
MODE[2:0] PULL-DOWN RESISTORS
R40
(MODE2)
R41
(MODE1)
R42
(MODE0)
000
10BASE-T Half Duplex
Auto-negotiation disabled
Populated
Populated
Populated
001
10BASE-T Full Duplex
Auto-negotiation disabled.
Populated
Populated
Unpopulated
010
100BASE-TX Half Duplex
Auto-negotiation disabled
CRS is active during Transmit & Receive
Populated
Unpopulated
Populated
011
100BASE-TX Full Duplex
Auto-negotiation disabled
CRS is active during Receive
Populated
Unpopulated
Unpopulated
100
100BASE-TX Half Duplex is advertised
Auto-negotiation enabled.
CRS is active during Transmit & Receive.
Unpopulated
Populated
Populated
101
Repeater mode (
)
Auto-negotiation enabled
100BASE-TX Half Duplex is advertised
CRS is active during receive
Unpopulated
Populated
Unpopulated
110
Power Down mode (
)
Unpopulated
Unpopulated
Populated
111
All capable. Auto-negotiation enabled (Default)
Unpopulated
Unpopulated
Unpopulated