KS8695X的應(yīng)用筆記支持額外的LED

　　The KS8695X offers 2 LED indicators per Ethernet port. Each of these LED indicators can be configured to indicate the following： Speed， Link， Full Duplex， Collision， Activity， Full Duplex/Collision， or Link/Activity. The LAN LEDs are configured in the KS8695X Switch Engine Control Register at offset 0xE800. Bits 27:25 control LANxLED1. Bits 24:22 control LANxLED0. The WAN LEDs are configured in the KS8695X WAN Miscellaneous Control Register at offset 0xEA0C. Bits 6:4 control WAN LED1， and bits 2:0 control WAN LED0. The programming values are shown below.

　　In the case where an extra LED is needed to support legacy implementations there are two solutions. The first is to use a single GPIO per port as the speed LED indicator. The second is to use just 2 GPIO and an external chip to provide a third LED indicator per port. This application note will address the second solution.