LAN8820 Datasheet, PDF (27/83 Pages) Microchip Technology – RGMII 10/100/1000 Ethernet Transceiver

LAN8820/LAN8820I
TABLE 3-9: REGISTER BITS IMPACTED BY THE MODE OF OPERATION (MOD)
Reg 19
[15:11]
Mode Definitions
00000 - RESERVED
10110
10111 All capable. Auto-negotiation enabled.
Auto master/slave resolution single port.
11000 All capable. Auto-negotiation enabled.
Auto master/slave resolution multi-port.
11001 All capable. Auto-negotiation enabled.
Manual master/slave resolution slave port.
11010 All capable. Auto-negotiation enabled.
Manual master/slave resolution master port.
11011 - RESERVED
11111
Reg 0
Reg 4
Reg 9
[13,12,8,6] [8,7,6,5] [12,11,10,9,8]
-
-
-
01X1
1111
00011
01X1
1111
01111
01X1
1111
10011
01X1
1111
11111
-
-
-
3.8.2 SOFTWARE CONFIGURATION
The Serial Management Interface (SMI) allows for the configuration and control of multiple transceivers. Several 16-bit
status and control registers are accessible through the management interface pins MDC and MDIO for 10/100/
1000Mbps operation. The device implements all the required MII registers and optional registers as described in Section
4.0, "Register Descriptions". Configuring the SMI address is described in Section 3.8.1.2.1. Refer to Section 3.4, "Serial
Management Interface (SMI)," on page 20 for additional information on the SMI.
3.9 Miscellaneous Functions
3.9.1 LEDS
The device provides the following LED signals to enable visual indication of status:
• 1000_LED
• 100_LED
• 10_LED
The Speed LEDs (1000_LED, 100_LED, 10_LED) are driven after a link is established. The functional operation of each
LED is detailed in TABLE 3-10:.
TABLE 3-10: LED OPERATION
LED
1000_LED
100_LED
10_LED
STATUS
On
Blinking
On
Blinking
On
Blinking
DESCRIPTION
1000BASE-T link
Transmit/receive activity
100BASE-T link
Transmit/receive activity
10BASE-T link
Transmit/receive activity
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DS00001871B-page 27