The card has some status LEDs. The bicolour LED lights red when the processor executes an external cycle to a local address, and green when the processor executes an external cycle to a cache address, the LED will be off if the CPU is executing out of its internal cache. The LEDs connected to the cache controller may be driven by the CPU directly, or are used as status signals by the controller. The normal state (and the reset state) is for the status indication. When under CPU control changing the LED state is a cache controller command, so completes in one cycle - this may be useful for triggering logic analysers etc.
The meanings of the other LEDs are:
