versus
JEDEC STAPL
Comparison Toolkit
Frank Toth
February 20, 2000
Agenda
 The latest on JEDEC STAPL
 JavaScan versus JEDEC STAPL
 Frequently Asked Questions
 Appendix
 Java API for Boundary-Scan
 JEDEC STAPL
 Lattice ispVM
®
www.xilinx.com
Combines the BEST Attributes of
IEEE-JTAG & JAVA
IEEE1149.1
JTAG
Utilizes existing JTAG infrastructures
and standards
Wide variety of devices now include
JTAG chain: CPUs, embedded
processors, DSPs, bus logic, and
Flash memory
Write Once Run Anywhere- One
file, multiple platforms
Web “friendly”: Facilitates
networked based download and
debug
Rich development tool suite
®
www.xilinx.com
The latest on JEDEC STAPL
 JEDEC voted STAPL in as a specification
 JAM name has been changed to STAPL because of copyright,
conflicts of interest with Altera “chairing the JEDEC committee”,
and other marketing advantage
 JEDEC JAM (STAPL)(2.1) is not compatible with original JAM (1.1):
All current users will need to be change to newer versions of
STAPL
 JEDEC STAPL STILL has limited compression & large memory
requirements (cannot be used with smaller embedded processors)
 JEDEC STAPL does not work with larger file sizes used in PROMs
and FPGAs, needs to be updated but…
— Bryon Moyer of Altera dissolved the JEDEC committee for now
®
www.xilinx.com
JavaScan versus JEDEC STAPL
Platform Independence
Write Once, Run Anywhere: One file,
multiple platforms, one standard
Network & Internet “friendly”
Proven Virtual Machines Exist for Nearly
Every Platform
Small Footprint
Fast & Efficient Tightly written code-10K
bytes easily fits on any 8 bit processor
Easily Integrated into Existing System
Extensible to Embedded & Personal Java:
User picks features
Infrastructure & Support
Road Tested and proven reliability
Fully supported 850 + engineers at Sun:
Long term commitment
Scalable & Flexible: Optimize compression,
data & I/O interfaces
Training & Tool support from Multiple
Vendors: Compilers, Code Coverage, Test
& Development Systems
Vendor and platform dependent
Favors Altera specific Programming & Data
Formats
Customized for each different revision of
Altera devices
STAPL Player is not platform independent
Large (5X) Footprint
50KBytes required- Will not fit in an 8 bit
processor
Code must be decompressed during run
time, must store compressed and
decompressed code
Major users (Teradyne) and PLD vendors
(Lattice/Vantis) have complained about
large code requirements for their PLDs and
platforms
No Infrastructure & Support: You are on your
own!
No tool support: Test & Development
systems do not exist
No updates & bug fixes except from
individual PLD vendor
®
www.xilinx.com
Frequently Asked Questions

Where can I get a quick comparison of Java versus JEDEC STAPL?
 The latest competitive alert is at:http://www.partner.xilinx.com/common/cpld/cpldcomp_info/alterajam.pdf

What is JEDEC STAPL and how does it compare to Altera’s Jam?
 JEDEC STAPL (Rev 2.1) does not look anything like the original (1997) JAM (Rev 1.1). Several large
changes have been made to the software and changes and updates are continuing. Customers will need
to make sure they have the latest revision running on their systems and embedded processors.

Where do I get a copy of the reference implementation of the Java API for Boundary-Scan and its
accompanying documentation?
 Follow this link http://www.xilinx.com/products/software/sx/sxpresso.html#Java API and then select the
link titled "Java API for Boundary-Scan - Reference Implementation”
(ftp://ftp.xilinx.com/pub/utilities/epld/jscan.zip). Download and unzip the file. You will find all the source
code, descriptive HTML documentation and javadoc generated collateral information to help you
understand the entire API.

How do I interface the Java API for Boundary-Scan to any arbitrary hardware?
 Follow this link http://www.xilinx.com/products/software/sx/sxpresso.html#Java API and then select the
link titled "Java API forBoundary-Scan - Reference Implementation"
(ftp://ftp.xilinx.com/pub/utilities/epld/jscan.zip). Download and unzip the file. will see a document entitled
"Java Native Interface Specification". This document describes the hardware interface calls and behavior.
Download the Java Developers Kit from the Java web site (http://java.sun.com/products/jdk/1.2/index.html
). Read the accompanying documentation about building and using Java Native Interface (JNI) methods.
Then simply code, compile and install a DLL or SO file that implements this interface and you are ready to
go.
®
www.xilinx.com
Appendix
Details on Competitors: JEDEC STAPL &
Lattice/Vantis ispVM
®
Java API for Boundary-Scan
provides a complete solution
Java
Algorithmic ControlFlow
Language
Compiler
Byte
Codes
Platform Independence
Small Footprint (10Kbytes)
Scalable from JavaCard to Enterprise Java
Java Virtual
Machine
Platform: Workstation/PC/Embedded
Java is proven technology
Road-Tested & Proven Reliability
Full suite of development tools & reference
material
®
www.xilinx.com
JEDEC STAPL
Provides only part of the solution
STAPL
Algorithmic ControlFlow
Language
(Under definition
by JEDEC)
All must be
supplied by the
end
customer
Proprietary
Compiler
Proprietary
Byte
Codes
STAPL
Virtual
Machine
(JAM Player)
Customer must supply debug and
interpreter
Current JEDEC STAPL (JEDEC name
for JAM) is 100% incompatible with
original Altera JAM
Run time memory requirements
balloon- Need to store compressed &
decompressed code
Compression scheme works well only
for Altera devices and cannot be
altered
C-Code
Compiler
Platform: Workstation/ PC
Embedded
®
www.xilinx.com
Lattice/Vantis ispVM
Only a partial solution. . .
What Lattice has been saying: “ Consensus for a virtual machinebased standardization effort appears to be building, as demonstrated by
Xilinx's Java API proposal”. Lattice Press Release: Sept. 24, 1998
Why not just use JavaScan?
Compiler and support tools
left up to the customer
Customer must supply run
time environment
No algorithmic control flow
language front end
Specification, capabilities and
features poorly define
Compiler
(customer written)
Byte
Codes
Virtual
Machine
Platform: Workstation/PC/Embedded
®
www.xilinx.com