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
Bits Description Type Default
15:0 SYM_ERR_CNT
The symbol error counter increments whe
never an invalid code symbol is
received (including IDLE symbols) in 100BASE-TX mode. The counter is
incremented only once per packet, even when the received packet contains
more than one symbol error. This counter increments up to 65,536 (2
16
) and
rolls over to 0 after reaching the maximum value.
Note: This re
gister is cleared on reset, but is not cleared by reading the
register. This register does not increment in 10BASE-T mode.
RO 0000h
2016 Microchip Technology Inc. DS00002165B-page 49
LAN8720A/LAN8720AI
4.2.11 SPECIAL CONTROL/STATUS INDICATIONS REGISTER
Index (In Decimal): 27 Size: 16 bits
Bits Description Type Default
15 AMDIXCTRL
HP Auto-MDIX control:
0 = Enable Auto-MDIX
1 = Disable Auto-MDIX (use 27.13 to control channel)
R/W 0b
14 RESERVED RO —
13 CH_SELECT
Manual channel select:
0 = MDI (TX transmits, RX receives)
1 = MDIX (TX receives, RX transmits)
R/W 0b
12 RESERVED RO —
11 SQEOFF
Disable the SQE test (Heartbeat):
0 = SQE test is enabled
1 = SQE test is disabled
R/W
NASR
0b
10:5 RESERVED RO —
4 XPOL
Polarity state of the 10BASE-T:
0 = Normal polarity
1 = Reversed polarity
RO 0b
3:0 RESERVED RO —
4.2.12 INTERRUPT SOURCE FLAG REGISTER
Index (In Decimal): 29 Size: 16 bits