hardware based tools are low level tools, do not involve the students
at uP component level design, in assembly programming or in instruction
set development. Additionally, the corresponding training kits restrict
the professor and student freedom for implementing and testing
educational experimental uP architectures. Moreover, despite the large
number of the available software based simulators (free or commercial
products), some critical drawbacks are still exist. These drawbacks
affect the learning capabilities of the students as well as the
simulation tool functionability, expandability and adaptability to
knowledge needs. Some
critical features of the existing simulation tools that introduce
The uP architecture under investigationis always fixed and based mainly
on a popular model. Thus, the uP model cannot be customized.
Only theoretical Approach.
The uP is approached theoretically (assembly programming). The students
do not have any view of the corresponding hardware. Additionally,
professors or students cannot build an experimental uP architecture.
Any possible extension is based on the source code intervention. Any
source code development by professors or students for the existing
simulators is almost impossible due to the high complexity or source
Individual uP components cannot be simulated (e.g., the experimental
behavior of a standalone register is too important for the
corresponding knowledge gain).
If the uP model architecture is fixed as well as the instruction set,
the students just follow predefined steps for the corresponding
The majority of the simulators are executed in PC based platforms, and
thus, a uP laboratory cannot be built without traditional PCs.
Regarding the above limitations, a new point of view is needed for
gaining more knowledge in the field by implementing a new approach and
developing a new educational tool. A similar simulator has been
proposed in Ref.  with many limitations such as: (i) lack of system
administration; (ii) no user interface; (iii) the assembly instruction
set has to be developed in binary mode; (iv) only low level operation;
and (v) not ready for educational use. In Ref.  the preliminary and
early version of the hardware based simulator has been presented. The
proposed HSP system in this paper, is the complete and mature HSP
system which is ready for the very first time for the educational
practice within the engineering curriculum in higher education.
new proposed tool combines software and hardware and the experimental
uP components are implemented in hardware. The hardware behavior is
defined by the corresponding software. The student or professor reuses
the available hardware components like bricks for developing an
experimental architecture. These components constitute the uP internal
units which interact as a system for performing assembly instruction
execution. The assembly instructions are also developed by students or
features of the proposed approach can be summarized as follows:
The proposed Hybrid Simulation Platform (HSP) works as a standalone low
cost solution without the need of a traditional PC (The HSP supervision
and control is achieved by a Raspberry Pi).
The HSP is an open source/hardware system where every component can be
reproduced and reprogrammed. A variety of uP models can be implemented
by developing/changing the component behavior, instruction set and
system architecture. Different educational scenarios based on a variety
of architectures, components and instructions can be created by
The students can now work on hardware level by connecting data, address
and control buses and viewing the corresponding signals at bit level.
Individual components can be investigated by students such as single
registers, ALUs and more. This knowledge is more critical when the work
flow is down-top.
The HSP can be extended by reproducing the same single hardware
components for building different architectures or by developing new
Source/Open architecture. The HSP is an open source and
open architecture project. The source code (Python and
will be available in the internet for free as well as the PCB
schematics for developing the needed hardware components. Thus, anyone
can make changes and experimenting with the desired features.
The proposed HSP tool is more suitable for inquiring learning which
nowadays constitutes a crucial approach where the students discover the
knowledge by studding data, experimenting with hardware/software
objects in cooperation with other colleagues. Thus, the student skills
will be emerged through a guided educational scenario.
The Multitech MPF-I is based on Z80 and the
corresponding assembly programming is performed only
through hexadecimal code. A great number of engineer
generations has been educated through these tools. In the
middle of 90's the above tools have been abandoned due to
model discontinuity, maintenance cost and student material
complexity. Moreover, the above hardware platforms do not
offer an architectural point of view for the corresponding uP
model. (photo by P. Papazoglou)
Software environments offer
great capabilities which include the selection of the uP
architecture under studding. (Screenshot by P. Papazoglou)
Physical view of a designed Experimental microprocessor
(Hybrid Simulation Platform)