User’s Manual
WIN Enterprises, Inc.
Feb., 2010
60
Appendix B: LAN Bypass Function (optional)
The power on default for CN19 & CN20 LAN ports is set to normal state.
How to control LAN 1&2 bypass function with watchdog timer
Please follow below steps to set the LAN bypass function control with watchdog
timer:
1. Setup jumper JP5
to 1-2 shorted
[default] to enable bypass function.
2. Setup JP4 to 2-3 to enable bypass function by watchdog timer.
3. Refer to Appendix A to set timer interval value and enable watchdog timer.
After setting the timer interval value, the watchdog timer begins to count down. You
have to refresh the watchdog timer, so that the watchdog timer will return to its initial
value; otherwise, your system will set CN19 & CN20 LAN ports to bypass state after
a time-out.
Note: Once the watchdog timer time-out you need to restart the system to reset the
timer.
How to control LAN 1&2 bypass function by GPIO
Please follow below steps to set the LAN bypass function control by GPIO:
1. Setup jumper JP5 to 1-2 shorted
[default] to enable bypass mode.
2. Setup JP4 to 1-2 [default] to enable bypass function by GPIO.
3. Refer to the program code and set CN19 & CN20 LAN ports to Bypass state or
Normal state.
LAN 1 & 2: GPIO20
Bypass state:
Normal state:
MOV DX, 050CH
IN EAX, DX
AND EAX, 0FFEFFFFFH
OUT DX, EAX
MOV DX, 050CH
IN EAX, DX
AND EAX, 0FFEFFFFFH
OR EAX, 00100000H
OUT DX, EAX
