dm9000b Davicom Semiconductor, Inc., dm9000b Datasheet - Page 28

• Manufacturer Part Number: dm9000b
• Description: Ethernet Controller With General Processor Interface
• Manufacturer: Davicom Semiconductor, Inc.

8.1 Basic Mode Control Register (BMCR) - 00
Final
Version: DM9000B-13-DS-F02
June 4, 2009
0.6-0.0
0.15
0.14
0.13
0.12
0.10
0.11
0.9
0.8
0.7
Bit
Auto-negotiation
Auto-negotiation
Speed selection
Duplex mode
Collision test
Power down
Loop-back
Bit Name
Reserved
Restart
enable
Isolate
Reset
0, RW/SC Reset
0,RW/SC
Default
0, RW
1, RW
1, RW
0, RW
0,RW
1,RW
0,RW
0,RO
1=Software reset
0=Normal operation
This bit sets the status and controls the PHY registers to their default
states. This bit, which is self-clearing, will keep returning a value of
one until the reset process is completed
Loop-back
Loop-back control register
1 = Loop-back enabled
0 = Normal operation
When in 100Mbps operation mode, setting this bit may cause the
descrambler to lose synchronization and produce a 720ms "dead
time" before receive
Speed Select
1 = 100Mbps
0 = 10Mbps
Link speed may be selected either by this bit or by auto-negotiation.
When auto-negotiation is enabled and bit 12 is set, this bit will return
auto-negotiation selected medium type
Auto-negotiation Enable
1 = Auto-negotiation is enabled, bit 8 and 13 will be in
auto-negotiation status
Power Down
While in the power-down state, the PHY should respond to
management transactions.
1=Power down
0=Normal operation
Isolate
Force to 0 in application.
Restart Auto-negotiation
1 = Restart auto-negotiation. Re-initiates the auto-negotiation
process. When auto-negotiation is disabled (bit 12 of this register
cleared), this bit has no function and it should be cleared. This bit is
self-clearing and it will keep returning to a value of 1 until
auto-negotiation is initiated by the DM9000B. The operation of the
auto-negotiation process will not be affected by the management
entity that clears this bit
0 = Normal operation
Duplex Mode
1 = Full duplex operation. Duplex selection is allowed when
Auto-negotiation is disabled (bit 12 of this register is cleared). With
auto-negotiation enabled, this bit reflects the duplex capability
selected by auto-negotiation
0 = Normal operation
Collision Test
1 = Collision test enabled. When set, this bit will cause the collision
asserted during the transmit period.
0 = Normal operation
Reserved
Read as 0, ignore on write
Ethernet Controller with General Processor Interface
Description
DM9000B
28