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Re: SIMH CPU-idleing support

On Thu, 18 Nov 2010 07:52:15 +0100 (CET)
Peter Svensson <petersv%psv.nu@localhost> wrote:

> SIMH detects the idle loop by detecting the number of cycles spent at a 
> specified IPL. I think. It can be adjusted (the SET IDLE NETBSD sets the 
> idle detector to wait for 1000 instructions at IPL 1 (ipl_mask=0x02)).

This is also the impression that I got reading the related SIMH code.
Also, after Der Mouse's reply I decided to do some searches and it
seems that in example code like the one at
http://pupgg.princeton.edu/cdrom12/html/ssb71/4556/4556p002.htm it
still indeed has to poll and wait regularily to simulate an "idle
enough" loop, confirming that a "proper" wait-for-interrupt instruction
is missing.

If SIMH can be adjusted for NetBSD-5 that'd still be great though, it's
worth looking into.

Thanks to all who replied,

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