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
2016 Microchip Technology Inc. DS00002165B-page 7
LAN8720A/LAN8720AI
TABLE 2-1: RMII SIGNALS
Num Pins Name Symbol
Buffer
Type
Description
1 Transmit
Data 0
TXD0 VIS The MAC transmits data to the transceiver using
this signal.
1 Transmit
Data 1
TXD1 VIS The MAC transmits data to the transceiver using
this signal.
1 Transmit
Enable
TXEN VIS
(PD)
Indicates that valid transmission data is present
on TXD[1:0].
1 Receive
Data 0
RXD0 VO8 Bit 0 of the 2 data bits that are sent by the trans-
ceiver on the receive path.
PHY Operat-
ing Mode 0
Configuration
Strap
MODE0 VIS
(PU)
Combined with MODE1 and MODE2, this config-
uration strap sets the default PHY mode.
See Note 2-3 for more information on configura-
tion straps.
Note: Refer to Section 3.7.2, "MODE[2:0]:
Mode Configuration," on page 30 for
additional details.
1 Receive
Data 1
RXD1 VO8 Bit 1 of the 2 data bits that are sent by the trans-
ceiver on the receive path.
PHY Operat-
ing Mode 1
Configuration
Strap
MODE1 VIS
(PU)
Combined with MODE0 and MODE2, this config-
uration strap sets the default PHY mode.
See Note 2-3 for more information on configura-
tion straps.
Note: Refer to Section 3.7.2, "MODE[2:0]:
Mode Configuration," on page 30 for
additional details.
1 Receive Error RXER VO8 This signal is asserted to indicate that an error
was detected somewhere in the frame presently
being transferred from the transceiver.
PHY Address
0
Configuration
Strap
PHYAD0 VIS
(PD)
This configuration strap sets the transceiver’s SMI
address.
See Note 2-3 for more information on configura-
tion straps.
Note: Refer to Section 3.7.1, "PHYAD[0]: PHY
Address Configuration," on page 26 for
additional information.