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 33
KSZ8081RNA/RND
1E.5 MDI/MDI-X
State
1 = MDI-X
0 = MDI
RO
1E.4 Energy
Detect
1 = Signal present on receive differential pair
0 = No signal detected on receive differential pair
RO 0
1E.3 PHY Isolate 1 = PHY in isolate mode
0 = PHY in normal operation
RW 0
1E.2:0 Operation
Mode Indica-
tion
[000] = Still in auto-negotiation
[001] = 10Base-T half-duplex
[010] = 100Base-TX half-duplex
[011] = Reserved
[100] = Reserved
[101] = 10Base-T full-duplex
[110] = 100Base-TX full-duplex
[111] = Reserved
RO 000
Register 1Fh – PHY Control 2
1F.15 HP_MDIX 1 = HP Auto MDI/MDI-X mode
0 = Microchip Auto MDI/MDI-X mode
RW 1
1F.14 MDI/MDI-X
Select
When Auto MDI/MDI-X is disabled,
1 = MDI-X mode
Transmit on RXP,RXM (Pins 4, 3) and Receive on
TXP,TXM (Pins 6, 5)
0 = MDI mode
Transmit on TXP,TXM (Pins 6, 5) and Receive on
RXP,RXM (Pins 4, 3)
RW 0
1F.13 Pair Swap
Disable
1 = Disable Auto MDI/MDI-X
0 = Enable Auto MDI/MDI-X
RW 0
1F.12 Reserved Reserved RW 0
1F.11 Force Link 1 = Force link pass
0 = Normal link operation
This bit bypasses the control logic and allows the
transmitter to send a pattern even if there is no link.
RW 0
1F.10 Power Sav-
ing
1 = Enable power saving
0 = Disable power saving
RW 0
1F.9 Interrupt
Level
1 = Interrupt pin active high
0 = Interrupt pin active low
RW 0
1F.8 Enable Jab-
ber
1 = Enable jabber counter
0 = Disable jabber counter
RW 1
1F.7 RMII Refer-
ence Clock
Select
1 = For KSZ8081RNA, clock input to XI (Pin 8) is
50MHz for RMII – 50MHz clock mode.
For KSZ8081RND, clock input to XI (Pin 8) is
25MHz for RMII – 25MHz clock code.
0 = For KSZ8081RNA, clock input to XI (Pin 8) is
25MHz for RMII – 25MHz clock code.
For KSZ8081RND, clock input to XI (Pin 8) is
50MHz for RMII – 50MHz clock mode.
RW 0
1F.6 Reserved Reserved RW 0
1F.5:4 LED Mode [00] = LED0: Link/Activity
[01] = LED0: Link
[10], [11] = Reserved
RW 00
1F.3 Disable
Transmitter
1 = Disable transmitter
0 = Enable transmitter
RW 0
TABLE 4-2: REGISTER DESCRIPTIONS (CONTINUED)
Address Name Description
Mode
Note 4-1
Default