Here we list some hardware Java processors that come in chip packages
(as opposed to cores that are sold as circuit
descriptions for implementation in different types of chips.)
Some of these chips need ancillary hardware such as power supplies,
memory, and so forth, but are basically complete microprocessors.
They implement Java bytecode instructions instead of conventional
processor type instructions.
Other Java chips work as co-processors that assist a conventional
processor to speed up the running of Java programs.
aJ-80 - aJile
The 32-bit aJ-100 derives from the JEMtm
Java processor first developed at Rockwell Collins. It executes
the full bytecode instruction set, including floating point, with
extended bytecodes for I/O and threading operations. It can also
implement custom bytecodes for special operations.
The processor core comes with 48 kB
internal memory (16kb for microcode and 32kb for data) and can
access up to 250MB external RAM via an 8-bit, 16-bit or 32 bit
interface. It s includes dual UARTs, five 8 bit I/0 ports, and
other I/O features.
It is suitable for real time operations and supports the RTSJ.
It offers a hard real-time multi-threading kernel with synchronization
and deterministic scheduling queues. The thread yield, wait, notify
and monitor enter/exit are implemented directly with extended
bytecodes so a RTOS is not needed to manage the threads. A thread
will yield to another within 1 microsecond.
The system can implement the J2ME Connected
Limited Device Configuration (CLDC) and for wireless systems can
run MIDLets. Two independent applications can run simultaneously
with no interference as if they were operating in two separate
JVMs. A timer allocates time slices to each JVM and a separate
timer is used by each JVM for thread time slices.
The company offers an optimizing linker/application builder with
a graphical user interface for creating programs for the system.
It will accept class files from other compilers. It statically
resolves class files and eliminates unnecessary methods and fields
to reduce memory requirements.
The aJ-80 provides essentially the same features as the aJ-100
but offers only an 8-bit memory interface with corresponding slower
Processor - Imsys
The Cjip processor provides a complete Java instruction set,
including floating point operations. The chip allows for reconfiguring
of internal microcode (even in real-time) and most bytecodes are
implemented in microcode. Instruction sets for C/C++ and assembler
are also included..
Virtual Peripherals (VPs) peform tasks such as timers,
I/O, graphics processing and many other services. A VP is loaded
at the microcode level and allow for fast, deterministic performance.
J2ME in the CLDC configuration and MIDP profile is supported.
We discuss the Imsys hardware also in the board
systems and show a demonstration
Stamp Interpreter Chip - Parallax
This chip is sold separately or as part of the Javelin
Stamp, which comes as a 24-pin DIP module (see the Javelin
Stamp section). The Stamp is nearly a complete computer system
with only the need for power and a serial line to begin computing.
The Java interpreter is created with
SX48BD microcontroller chip. The chip translates Java bytecodes
(actually, a subset of them) into the SX48 instructions and executes
See also the section on the Javelin Stamp
and Demo1 & Demo
2 Javelin Stamp example applications.
Multimedia Application Processor - Nazomi
This processor comes in a standard 16-bit SRAM/FLASH memory package
and plugs into the SRAM bus. It then acts as a co-processor to
accelerate Java programs, particularly multimedia applications
References & Web Resources
Latest update: Dec. 15, 2004