AIM104-COM8 Technical Manual
Jumpers
© 2007 Eurotech Ltd Issue C
13
JP1 - Interrupt selection
The JP1 jumper is used to set the IRQ line for each group of four serial port channels.
The A position is used for channels 0-3 and the B position for channels 4-7.
JP1
Line
Function when fitted
IRQ3
Routes IRQ line to IRQ3
IRQ4
Routes IRQ line to IRQ4
IRQ5
Routes IRQ line to IRQ5
IRQ7
Routes IRQ line to IRQ7
IRQ9
Routes IRQ line to IRQ9
IRQ10
Routes IRQ line to IRQ10
IRQ11
Routes IRQ line to IRQ11
IRQ12
Routes IRQ line to IRQ12
IRQ14
Routes IRQ line to IRQ14
IRQ15
Routes IRQ line to IRQ15
A
B
When jumper JP3 (see page
) is set to ‘IRQ’, side A is for all channels and the signal
on side B becomes tri-stated so that it does not interrupt on both sides. In this case,
the link on side B should be removed.
Channels 0-3 share the same interrupt line, while 4-7 share another.
You cannot, for instance, set COM1/COM3 to use IRQ4 and COM2/COM4
to use IRQ3, which are the PC defaults.
