[ECOS] i386 affects IRQ lines?

[Bob Holmberg <bob_holmberg at yahoo dot com>]

Hello,

I am using eCos for servo control and need to 
have a 500 Hz servo loop.  I have an I/O card
(ServoToGo) which generates low pulses on the
IRQ11 (configurable) that I observe on an
ocsilliscope.  The problem is that it appears
that eCos causes the IRQ11 line to go low 
when it exits main.cxx after exiting my
cyg_user_start().  In the mean time, the servo
thread has initialized and paused at a 
cyg_semaphore_wait() -- ie. my servo tick.

I didn't think eCos would be able to affect the
state of the IRQ lines directly, but I have ruled
out everything else.  When I use the debugger, 
I can get the pulses on the IRQ11 line to start,
then I hit the reset line on the PC and the pulses
continue throughout the bios, and redboot startup.
Only when I start my application code, during the
eCos initialization, before I get to my application
code, the IRQ pulses are replaced by a steady low 
on the IRQ line.

I have followed the examples for interrupts, ISR,
and DSR in the Massa book, and read the updates 
to the documention here.  

I am looking for suggestions of new approaches
to get my ISR/DSR to be triggered by the external
IRQ interrupt.

My setup:
-Intel PII 450MHz Single Board Computer
-ISA I/O card (ServoToGo) at 0x300 with 82C59
interrupt controller.  It is set up to generate IRQ
pulses
without being acknowledged by the CPU.
-eCos 2.0 beta updated from CVS 09-May-2003
-template: i386 PC target, with net package

Regards,
Bob Holmberg


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