Lpc2000

System mode is user mode with the ability to modify the status register.
As Michael mentions if you want to re-enable interrupts from IRQ mode
you should switch to system mode to stop the banked IRQ registers from
being corrupted - there is an app note on the ARM web site that goes
into this.

The CrossWorks startup code and tasking library run the processor in
System mode by default - I would guess most other systems would do
similar as well.

Use of the swi instruction (which could be what luvpc2129 means by
making a system call) will switch to supervisor (SVC) mode.

Regards
Michael

Date: Mon, 16 Feb 2004 19:19:54 -0000
   From: "luvpc2129" <luvpc2129@...>
Subject: Re: System mode

 Use of system calls will put lpc2100 in the system mode.


-- In lpc2100@yahoogroups.com, Michael Pont <Michael.Pont@t...> wrote:
> 
> Hi,
> 
> Can anyone tell me when I should expect to put an LPC2100 device 
into "system mode"?
> 
> I can see one use (in systems where there are multiple IRQ 
interrupts).
> 
> Any other suggestions?
> 
> Michael.