Datasheet
Table Of Contents
- Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support
- 1.0 Introduction
- 2.0 Pin Description and Configuration
- 3.0 Functional Description
- 3.1 Transceiver
- 3.2 Auto-negotiation
- 3.3 HP Auto-MDIX Support
- 3.4 MAC Interface
- 3.5 Serial Management Interface (SMI)
- 3.6 Interrupt Management
- 3.7 Configuration Straps
- 3.8 Miscellaneous Functions
- 3.9 Application Diagrams
- 4.0 Register Descriptions
- 4.1 Register Nomenclature
- 4.2 Control and Status Registers
- TABLE 4-2: SMI Register Map
- 4.2.1 Basic Control Register
- 4.2.2 Basic Status Register
- 4.2.3 PHY Identifier 1 Register
- 4.2.4 PHY Identifier 2 Register
- 4.2.5 Auto Negotiation Advertisement Register
- 4.2.6 Auto Negotiation Link Partner Ability Register
- 4.2.7 Auto Negotiation Expansion Register
- 4.2.8 Mode Control/Status Register
- 4.2.9 Special Modes Register
- 4.2.10 Symbol Error Counter Register
- 4.2.11 Special Control/Status Indications Register
- 4.2.12 Interrupt Source Flag Register
- 4.2.13 Interrupt Mask Register
- 4.2.14 PHY Special Control/Status Register
- 5.0 Operational Characteristics
- 6.0 Package Information
- 7.0 Application Notes
- Appendix A: Data Sheet Revision History
- The Microchip Web Site
- Customer Change Notification Service
- Customer Support
- Product Identification System
- Worldwide Sales and Service
FIGURE 1-1: SYSTEM BLOCK DIAGRAM
LAN8720A/
LAN8720Ai
10/100
Ethernet
MAC
RMII
Mode LED
Transformer
Crystal or
Clock
Oscillator
MDI
RJ45
FIGURE 1-2: ARCHITECTURAL OVERVIEW
RMII Logic
Interrupt
Generator
LEDs
PLL
Receiver
DSP System:
Clock
Data Recovery
Equalizer
Squeltch
& Filters
Analog-to-
Digital
10M RX
Logic
100M RX
Logic
100M PLL
10M PLL
Transmitter
10M
Transmitter
100M
Transmitter
10M TX
Logic
100M TX
Logic
Central Bias
PHY Address
Latches
LAN8720A/LAN8720Ai
RBIAS
LED1
nINT
XTAL2
XTAL1/CLKIN
LED2
Management
Control
Mode Control
Reset Control
MDIX
Control
HP Auto-MDIX
RXP/RXN
TXP/TXN
TXD[0:1]
TXEN
RXD[0:1]
RXER
CRS_DV
MDC
MDIO
Auto-
Negotiation
RMIISEL
nRST
MODE[0:2]
SMI
PHYAD0
2016 Microchip Technology Inc. DS00002165B-page 5
LAN8720A/LAN8720AI