Chapter 4 System Status LEDs Indicator & SW1
How do the LEDs light when system is booting?
There are 3 statuses when system is booting,
a. All three LEDs will light after system power-up;
b. The right LED will be dark. It means that system is run POST;
c. 2 LEDs on the right side will be dark. It means POST is complete. At this time, you
can press “DEL” key to enter BIOS menu to change setting as your required.
How to use the status indicator LEDs and Micro switch SW1?
After system completed boot, enter I/O space based address 500H and change some
register value as follow:
LED16
1. Set 5000H+0CH, bit7
2. the LED will light
3. clear the 500H+0CH, bit7
4. the LED will dark
LED17
1. Set 500H+0CH, bit6
2. the LED will light
3. clear the 500H+0CH, bit6
4. the LED will dark
LED6
1. Set 500H+0FH, bit28
2. the LED will light
3. clear the 500H+0FH, bit28
4. the LED will dark
SW1
1. Set 500H+0DH, bit13 ,means direction is input
2. press SW1 ,then 500H+0DH ,bit13 will be changed to 0
3. when SW1 release, 500H+0DH ,bit13 will be changed to 1 (default)
CN6 7-8pin GPIO
As output
1. Clear 500H+0DH, bit13, means direction is output
2. Set 500H+0DH, bit13 ,CN6 7pin will be changed to 1 (High level)
3. Clear 500H+0DH, bit13 ,CN6 7pinwill be changed to 0 (low level)
As input