PicoJava

picoJava is a microprocessor specification dedicated to native execution of Java bytecode without the need for an interpreter or just-in-time compilation. The aim is to speed bytecode execution up by up to 20 times, compared to standard Intel CPU with a Java virtual machine. ^[1] GNU Compiler Collection added picoJava support in 1999 as machine definition 'pj,'. ^[2] The open-source version of picoJava has been implemented in an FPGA. ^[3]

Creation

Picojava was developed by Sun Microsystems, the first version of the specification was created in 1997 ^[4] . This first version was never released as a product by Sun ^[4] . A redesign of Picojava in 1999 would give birth to Picojava-II, which is freely available and has a rich documentaion. ^{[5] [6]}

See also

• Jazelle
• MAJC

Notes

1. "What is picoJava? Webopedia Definition". www.webopedia.com. 10 June 1999. Retrieved 2017-06-04.
2. "Patch: Support for picoJava". gcc-patches (Mailing list). 22 Oct 1999.
3. Puffitsch, W. and Schoeberl, M. 2007. picoJava-II in an FPGA. In Proceedings of the 5th international Workshop on Java Technologies For Real-Time and Embedded Systems (Vienna, Austria, September 26–28, 2007). JTRES '07, vol. 231. ACM, New York, NY, 213-221. http://doi.acm.org/10.1145/1288940.1288972
4. Schoeberl, Martin; Puffitsch, Wolfgang. "picoJava-II in an FPGA" (PDF). jopdesign.com. Retrieved 2 October 2025.
5. picoJava-II™ Microarchitecture Guide (PDF). Sun. 1999. Retrieved 2 October 2025.
6. picoJava-II™ Programmer’s Reference Manual (PDF). Sun. 1999.

References

• McGhan, Harlan; O’Connor, Mike (October 1998). "PicoJava: A Direct Execution Engine For Java Bytecode". Computer , Volume 31, Issue 10: pp. 22–30.
• O’Connor, J. Michael; Tremblay, Marc (March/April 1997). "picoJava-I: The Java Virtual Machine in Hardware". IEEE Micro , Volume 17, Issue 2: pp. 45–53.
• Hangal, Sudheendra; O'Connor, J. Michael (May/June 1999). "Performance analysis and validation of the picoJava processor." IEEE Micro , Volume 19, Issue 3.

External links

• picoJava at Sun Community Source Licensing (SCSL)
• Release announcement (Fujitsu)