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 15
KSZ8081RNA/RND
3.2.2.2 RMII – 50 MHz Clock Mode
The KSZ8081RND is configured to RMII – 50 MHz clock mode after it is powered up or hardware reset with the follow-
ing:
• An external 50 MHz clock source (oscillator) connected to XI (Pin 8)
The KSZ8081RNA can optionally be configured to RMII – 50 MHz clock mode after it is powered up or hardware reset
and software programmed with the following:
• An external 50 MHz clock source (oscillator) connected to XI (Pin 8)
• Register 1Fh, Bit [7] programmed to ‘1’ to select RMII – 50 MHz clock mode
FIGURE 3-3: KSZ8081RNA/RND RMII INTERFACE (RMII - 50 MHZ CLOCK MODE)
KSZ8081RNA/RND
CRS_DV
RXD[1:0]
RXER
TXD[1:0]
RMII MAC
CRS_DV
RXD[1:0]
TXD[1:0]
RX_ER
REF_CLK
TXEN TX_EN
XI
50MHz
OSC