A Java processor is the implementation of the
Java virtual machine
A Java virtual machine (JVM) is a virtual machine that enables a computer to run Java programs as well as programs written in other languages that are also compiled to Java bytecode. The JVM is detailed by a specification that formally describes ...
(JVM) in hardware. In other words, the
Java bytecode that makes up the instruction set of the abstract machine becomes the instruction set of a concrete machine. These were the most popular form of a
high-level language computer architecture, and were "an attractive choice for building embedded and real-time systems that are programmed in Java".
However, as of 2017, embedded Java is "pretty much dead" and no realtime Java chip vendors exist.
Implementations
There are several research Java processors tested on FPGA, including:
*
picoJava was the first attempt to build a Java processor, by
Sun Microsystems
Sun Microsystems, Inc. (Sun for short) was an American technology company that sold computers, computer components, software, and information technology services and created the Java programming language, the Solaris operating system, ZFS, the ...
. Its successor picoJava-II was freely available under the
Sun Community Source License,
[ and is still available from some archives.
* provides hardware support for object-oriented functions
* Java Optimized Processor for ]FPGA
A field-programmable gate array (FPGA) is an integrated circuit designed to be configured by a customer or a designer after manufacturinghence the term '' field-programmable''. The FPGA configuration is generally specified using a hardware de ...
s. A PhD thesis i
available
and it has been used in several commercial applications.[ In 2019 it was extended to be energy aware (EAJOP).
Some commercial implementations included:
* The aJile processor was the most successful ]ASIC
An application-specific integrated circuit (ASIC ) is an integrated circuit (IC) chip customized for a particular use, rather than intended for general-purpose use, such as a chip designed to run in a digital voice recorder or a high-efficien ...
Java processor.[
*Cjip from Imsys Technologies. Available on boards and with wireless radios from AVIDwireless]["Imsys hedges bets on Java: rewritable-microcode chip has instruction sets for Java, Forth, C/C++"]
by Tom R. Halfhil]
* ARM9E, ARM926EJ-S is an ARM processor able to run Java bytecode, this technology being named '' Jazelle''
References
{{Reflist
Java virtual machine
High-level language computer architecture