Datasheet

LAN8740A/LAN8740Ai
DS00001987A-page 60  2013-2015 Microchip Technology Inc.
4.2.1 BASIC CONTROL REGISTER
Note 1: The default value of this bit is determined by the MODE[2:0] configuration straps. Refer to Section 3.7.2,
"MODE[2:0]: Mode Configuration" for additional information.
Index (In Decimal): 0 Size: 16 bits
Bits Description Type Default
15 Soft Reset
1 = Software reset. Bit is self-clearing. When setting this bit do not set other
bits in this register.
Note: The configuration (as described in Section 3.7.2, "MODE[2:0]:
Mode Configuration") is set from the register bit values, and not
from the mode pins.
R/W
SC
0b
14 Loopback
0 = Normal operation
1 = Loopback mode
R/W 0b
13 Speed Select
0 = 10 Mbps
1 = 100 Mbps
Note: Ignored if auto-negotiation is enabled (0.12 = 1).
R/W (see Note 1)
12 Auto-Negotiation Enable
0 = Disable auto-negotiate process
1 = Enable auto-negotiate process (overrides 0.13 and 0.8)
R/W (see Note 1)
11 Power Down
0 = Normal operation
1 = General power down mode
R/W 0b
10 Isolate
0 = Normal operation
1 = Electrical isolation of PHY from the MII/RMII
R/W 0b
9 Restart Auto-Negotiate
0 = Normal operation
1 = Restart auto-negotiate process
Note: Bit is self-clearing.
R/W
SC
0b
8 Duplex Mode
0 = Half duplex
1 = Full duplex
Note: Ignored if Auto-Negotiation is enabled (0.12 = 1).
R/W (see Note 1)
7 Collision Test
0 = Disable COL test
1 = Enable COL test
R/W 0b
6:0 RESERVED RO -