Re: [Simulavr-devel] SimulAVR + simulated hardware

[Bruce R'. Miller]

On Wednesday 24 December 2003 21:23, Theodore A. Roth wrote:
> Why would time need to be sent in either direction? In a real application,
> time is not shared unless you have multiple devices running off of a single
> crystal.

Theoretically true, but timing information is important if you want to 
accurately simulate the hardware.  The real CPU will take a different path in 
a differant timing situation.  In theory we should be making assumptions like 
"this code will complete before that external interrupt fires" but that's the 
way it happens when you don't have an operating system to run defence for 
you.  The devices on the board make not share an actual clock signal but 
there is an implicit shared clock due to the physical nature of the devices.

> Do you have an example of a case where the hook would need to pass clock
> info back?

In most interesting cases, I should think.  I have a digital pressure sensor 
that takes a fair amount of time to respond once I poke it.  

-b