Boundary scan description language (BSDL) is a
hardware description language
In computer engineering, a hardware description language (HDL) is a specialized computer language used to describe the structure and behavior of electronic circuits, and most commonly, digital logic circuits.
A hardware description language e ...
for electronics testing using
JTAG
JTAG (named after the Joint Test Action Group which codified it) is an industry standard for verifying designs and testing printed circuit boards after manufacture.
JTAG implements standards for on-chip instrumentation in electronic design autom ...
. It has been added to the
IEEE
The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operati ...
Std. 1149.1, and BSDL files are increasingly well supported by JTAG tools for boundary scan applications, and by test case generators.
BSDL overview
BSDL was a subset of
VHDL
The VHSIC Hardware Description Language (VHDL) is a hardware description language (HDL) that can model the behavior and structure of digital systems at multiple levels of abstraction, ranging from the system level down to that of logic gat ...
.
However, since IEEE 1149.1-2013, it is no longer a "proper" subset of VHDL but it is considered based on VHDL.
It is formally defined in IEEE Standard 1149.1 Annex B. Each BSDL file describes one version of an
IC and has many package pin maps as are available for a particular
die. This is necessary because, for example, two different
BGA packages will have different balls; even if the ball has the same name it may be bonded to a different signal on the other package, and sometimes bondings change between revisions.
Each digital signal (pin or ball) on the package is defined, as are the
registers and opcodes used in an
IEEE
The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operati ...
1149.1, IEEE 1149.6, IEEE 1149.8.1, IEEE 1532 and IEEE 1149.4 compliant IC. There is one instruction register, a minimum of a 1-bit bypass register, one boundary scan register and optionally a 32 bit device_id register. The registers other than the instruction register are called TDRs or Test Data Registers. The boundary scan register (BSR) is unique as it is the register which is also mapped to the I/O of the device. Many of the BSDL definitions are sets of single long string constants.
Note that registers not involved in boundary scan are often not defined. Instructions that are not publicly defined are included in the INSTRUCTION_PRIVATE section.
Microprocessor
A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circu ...
register descriptions in BSDL typically do not include enough information to aid in building a 1149.1 based
emulator
In computing, an emulator is hardware or software that enables one computer system (called the ''host'') to behave like another computer system (called the ''guest''). An emulator typically enables the host system to run software or use peri ...
or
debugger
A debugger or debugging tool is a computer program used to test and debug other programs (the "target" program). The main use of a debugger is to run the target program under controlled conditions that permit the programmer to track its execut ...
.
External links
Free BSDL Compiler - Validates Grammar, Semantics and Syntax according to IEEE standard rulesBSDL & SVF file formats, functions and features
References
Electronics manufacturing
Hardware testing
Printed circuit board manufacturing
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