ADLINK Technology cPCI-6910 Series, Руководство пользователя

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Watchdog Timer 73
cPCI-6910 Series
WDT LED light
Sets bit 25 of GP 04H to 0. Bit 25 of GP
0CH determines the state of WDT LED (0 = on, 1 = off).
WDT LED blink
Sets bit 25 of GP 04H to 0. Bit 25 of GP
18H enables the WDT LED to blink (0 = function normally, 1 =
enable blinking). The high and low times have approximately
0.5 seconds each.
WDT Programming Procedure
1. Enable the Watchdog Timer option in the BIOS (Inte-
grated Peripherals > Onboard Device).
2. Make sure that the WDT_TOUT# signal is functional (not
GPIO32 function).
3. Enable the WDT output, pre-scaler, and interrupt type in
the WDT configuration register.
4. Obtain control base from Base Address register.
5. Program Preload register’s value according to the
unlocking sequence.
6. Set the WDT timer mode in the WDT Lock Register.
7. Enable WDT from the WDT Lock register and program
the WDT LED functionality.
To prevent the timer from causing an interrupt or driving
WDT_TOUT#, the timer must be reloaded periodically. The fre-
quency of reloads required is dependent on the value of the pre-
load values. To reload the down-counter, the register unlocking
sequence must be performed.
If the user wishes to disable WDT, set bit 1 of WDT Lock Register
to 0.