Re: [ECOS] Finding Interrupt Vector Number for PIT

[Bart Veer <bartv at ecoscentric dot com>]

>>>>> " " == AbdullahKhateeb Khan <khateeb4u@yahoo.com> writes:

 > I am using Intel P-4 Desktop computer as a target. My host
 > platform is an i386-pc (window based)

 > #define PC_PIT_CONTROL  (0x43)
 > #define PC_PIT_CLOCK_0	(0x40)
 > #define PC_PIT_CLOCK_1	(0x41)
 > #define PC_PIT_CLOCK_2	(0x42)

 > The above mentioned piece of code is taken from "var_intr.h". It
 > shows that Programmable Interval Timer (PIT) includes three
 > seperate timers. The addresses 0x40, 0x41, 0x42, 0x43 are the I/O
 > addresses used to program these timers. I know how to program these
 > Timers in different modes.

 > To program any of these timers to generate interrupt and to map an
 > ISR at its interrupt i need to know the interrupt vector number
 > where i have to store the address of ISR.

 > How can i find the interrupt vector number of PC_PIT_CLOCK_0?

CYGNUM_HAL_INTERRUPT_TIMER. The interrupt vectors are always #define'd
directly or indirectly in <cyg/hal/hal_intr.h>. For a PC target
hal_intr.h #include's var_intr.h #include's plf_intr.h #include's
pcmb_intr.h, which defines all the interrupt vectors for a standard PC
target.

Note that on a standard PC only the first timer is hooked up to the
interrupt controller. The other two timers cannot generate interrupts.
For more information on PC hardware you can consult a standard
reference such as Messmer's "The Indispensable PC Hardware Book".
That first timer is normally used for the eCos system clock so is not
available to application code.

Bart

-- 
Bart Veer                       eCos Configuration Architect
http://www.ecoscentric.com/     The eCos and RedBoot experts


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