How to enable PIC-2

[pepito]

I can't activate the CMOS Real Time Clock periodic interrupt. I read some tutorials and I belive I am follow the necessary steps to do it, then I suspect I have some error enabling the PIC-2 (IRQ8-IRQ15).

What is necessary to enable PIC-2?

Thank you,
pepito

[CodeSlasher]

in order to receive interrupts from the slave pic, you need to enable IRQ line 2 which the slave pic is cascaded on. Also in your initialization code for the master pic, make sure you tell it to cascase the slave on irq line 2.
Hope this helps

[pepito]

Thank you!

How may I tell the PIC-1 to cascase the slave on irq line 2?

pepito

[CodeSlasher]

By default its supposed to be cascaded on irq line 2. but its better to be safe and add it in the setup sequence sent to the master pic. Its one of the control words written to the master pic (i.e a set bit in one of them) can't remember but any doc explaining the pic and its setup should have the info.

[pepito]

Thank you very much for your response!  I will see the PIC documents...

pepito