Fastwel CPB902, User Manual

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Functional Description CPB902
C P B 9 0 2 U s e r M a n u a l
62
© 2 0 0 8 F a s t w e l v . 1 . 5 b E
4.3.14 Optoisolated Reset/Interrupt
The module has one optoisolated discrete input J14, which can be used for remote reset or for
interrupt generation. This interrupt is served by IRQ14 line of the interrupt controller. Use J13
jumpers to select the microprocessor reset source and to enable the interrupt generation by the
signal from the optoisolated input. Remote reset source voltage is 3 – 5 V. Figure 4.28 presents a
simplified diagram of the circuits. J13 jumper settings are described in the Table 4.20.
Figure 4.28: Reset Source Selection and Optoisolated Input Circuit Diagram
Optoisolated Reset/IRQ Input
WDT
SIO
&
1
CPU RESET
IRQ
+3.3V
+3.3V
J14
1
2
1 2
3 4
5 6
7 8
/SIO_WDT
/SV_WDT
/MPR_RESET
OPT O_IRQ
J13
E
3- 5V
470
S1
Table 4.20: J13 Settings: Switching Reset/IRQ Source
Closed contacts Function
1-2 Enable Reset from supervisor's WDT
3-4 Enable Reset from SIO WDT
5-6 Enable the optoisolated input as a Reset source
Enable Reset from the optoisolated input
7-8 Enable the optoisolated input as an IRQ14 interrupt source.
IRQ14 interrupt can be used only if Primary IDE channel is disabled
in BIOS Setup (see
section 5.5 )
It is not allowed to close the contacts 5-6 and 7-8 simultaneously, the optoisolated input can have
only one assignment. The jumpers 1-2, 3-4, and 5-6 can be set closed together. In this case, the
resulting active low Reset signal for the microprocessor is formed as logic OR function based on
incoming signals. The supervisor issues Reset signal when the power voltage drops below the
specified value or when the connected to the supervisor SW1 button is pressed (see Components
Layout Diagram,
Figure 4.2 ).
Starting from BIOS version 2.7, it is possible to route OptoIRQ signal to NMI input. See bit 7 of
310h register description in Table 4.3. OptoIRQ signal status is represented by bit 0 of 302h
register.