Virtuoso User Manual - ClassicCMP

Virtuoso : an overview
3. Virtuoso : an overview
3.1. Requirements for a programming system
Processor technology is changing very rapidly. Processors are becoming
faster, microcontrollers are becoming more complex and richer in features,
but developers are left with the impossible task to keep up. In addition fundamental
I/O bandwidth limitations force the designers to go parallel to reach
the required level of performance. The conclusion is clear : the only way to
shorten the development cycle is to use tools that relieve the developer from
the technology change. The ideal development tool must not only provide for
faster application development by giving the programmer a head start, but
should also be future proof. The requirements can be split in three areas :
1. A consistent high level API across all target processors
2. The utilities to debug and maintain the code
3. Target processor specific support for best performance.
3.2. The high level view : a portable set of services
3.2.1. A multi-tasking real-time microkernel as the essential module
In many applications sensors supply raw data, preprocessing algorithms filter
and examine the data, control algorithms process the data and deduce
from it control commands, while additional functions deal with user interaction,
data logging or safety concerns. In most cases tight timing requirements
need to be fulfilled especially if the system has to deal with events that
can happen at any time, regardless of the current function being executed at
that moment. A common and proven solution is to map the different functions
onto separate tasks, assign priorities to these tasks and to use a standardized
way of defining the interaction between the tasks. The core of this solution
is the availability of a real-time microkernel that manages the timely
execution of the tasks and their interactions in a way that frees the applications
programmer from the burden of doing it himself. It must also be noted
that for multiprocessor targets, multitasking is a must to achieve high performance
because without it, it is not possible to overlap computation and calculation.
As such the microkernel must correctly provide for priority driven
preemptive scheduling of the tasks, permit to transfer data between the
tasks in a synchronous and asynchronous way, coordinate tasks, deal with
timed events, allocate memory and protect common resources. In addition,
the microkernel should be small, secure and flexible while providing a very
fast response. Practice has shown that in general the same set of microkernel
services is sufficient.
P1 - 10 Virtuoso User Manual Copyright 1996 Eonic Systems