Datasheet
Table Of Contents
- 1.0 Introduction
- 2.0 Pin Description and Configuration
- 3.0 Functional Description
- 3.1 10BASE-T/100BASE-TX Transceiver
- 3.2 RMII Interface
- 3.3 Back-to-Back Mode – 100 Mbps Copper Repeater
- 3.4 MII Management (MIIM) Interface
- 3.5 Interrupt (INTRP)
- 3.6 HP Auto MDI/MDI-X
- 3.7 Loopback Mode
- 3.8 LinkMD® Cable Diagnostic
- 3.9 NAND Tree Support
- 3.10 Power Management
- 3.11 Reference Circuit for Power and Ground Connections
- 3.12 Typical Current/Power Consumption
- 4.0 Register Descriptions
- 5.0 Operational Characteristics
- 6.0 Electrical Characteristics
- 7.0 Timing Diagrams
- 8.0 Reset Circuit
- 9.0 Reference Circuits — LED Strap-In Pins
- 10.0 Reference Clock - Connection and Selection
- 11.0 Magnetic - Connection and Selection
- 12.0 Package Outline
2016 Microchip Technology Inc. DS00002199A-page 27
KSZ8081RNA/RND
0.12 Auto-Negoti-
ation Enable
1 = Enable auto-negotiation process
0 = Disable auto-negotiation process
If enabled, the auto-negotiation result overrides the
settings in Registers 0.13 and 0.8.
RW Set by the ANEN_-
SPEED strapping pin.
See the Strap-In
Options -
KSZ8081RNA/RND
section for details.
0.11 Power-Down 1 = Power-down mode
0 = Normal operation
If software reset (Register 0.15) is used to exit
power-down mode (Register 0.11 = 1), two soft-
ware reset writes (Register 0.15 = 1) are required.
The first write clears power-down mode; the sec-
ond write resets the chip and re-latches the pin
strapping pin values.
RW 0
0.10 Isolate 1 = Electrical isolation of PHY from MII
0 = Normal operation
RW 0
0.9 Restart Auto-
Negotiation
1 = Restart auto-negotiation process
0 = Normal operation.
This bit is self-cleared after a ‘1’ is written to it.
RW/SC 0
0.8 Duplex Mode 1 = Full-duplex
0 = Half-duplex
RW 1
0.7 Collision Test 1 = Enable COL test
0 = Disable COL test
RW 0
0.6:0 Reserved Reserved RO 000_0000
Register 1h - Basic Status
1.15 100Base-T4 1 = T4 capable
0 = Not T4 capable
RO 0
1.14 100Base-TX
Full-Duplex
1 = Capable of 100Mbps full-duplex
0 = Not capable of 100Mbps full-duplex
RO 1
1.13 100Base-TX
Half-Duplex
1 = Capable of 100Mbps half-duplex
0 = Not capable of 100Mbps half-duplex
RO 1
1.12 10Base-T
Full-Duplex
1 = Capable of 10Mbps full-duplex
0 = Not capable of 10Mbps full-duplex
RO 1
1.11 10Base-T
Half-Duplex
1 = Capable of 10Mbps half-duplex
0 = Not capable of 10Mbps half-duplex
RO 1
1.10:7 Reserved Reserved RO 000_0
1.6 No Preamble 1 = Preamble suppression
0 = Normal preamble
RO 1
1.5 Auto-Negoti-
ation Com-
plete
1 = Auto-negotiation process completed
0 = Auto-negotiation process not completed
RO 0
1.4 Remote Fault 1 = Remote fault
0 = No remote fault
RO/LH 0
1.3 Auto-Negoti-
ation Ability
1 = Can perform auto-negotiation
0 = Cannot perform auto-negotiation
RO 1
1.2 Link Status 1 = Link is up
0 = Link is down
RO/LL 0
1.1 Jabber
Detect
1 = Jabber detected
0 = Jabber not detected (default is low)
RO/LH 0
TABLE 4-2: REGISTER DESCRIPTIONS (CONTINUED)
Address Name Description
Mode
Note 4-1
Default