Boundary scan description language
Encyclopedia
Boundary scan description language (BSDL) is a description language for electronics testing using JTAG. It has been added to the IEEE Std. 1149.1, and BSDL files are increasingly well supported by JTAG tools for boundary scan applications, and by test case generators.
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 a IEEE 1149.1, IEEE 1149.6, 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
register descriptions in BSDL typically do not include enough information to aid in building a 1149.1 based emulator
or debugger
.
BSDL Overview
BSDL is a VHDL subset. Each BSDL file describes one version of an ICIntegrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
and has many package pin maps as are available for a particular die
Die (integrated circuit)
A die in the context of integrated circuits is a small block of semiconducting material, on which a given functional circuit is fabricated.Typically, integrated circuits are produced in large batches on a single wafer of electronic-grade silicon or other semiconductor through processes such as...
. This is necessary because, for example, two different BGA
Ball grid array
A ball grid array is a type of surface-mount packaging used for integrated circuits.- Description :The BGA is descended from the pin grid array , which is a package with one face covered with pins in a grid pattern. These pins conduct electrical signals from the integrated circuit to the printed...
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
Hardware register
In digital electronics, especially computing, a hardware register stores bits of information, in a way that all the bits can be written to or read out simultaneously.The hardware registers inside a central processing unit are called processor registers....
and opcodes used in a IEEE 1149.1, IEEE 1149.6, 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
Microprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...
register descriptions in BSDL typically do not include enough information to aid in building a 1149.1 based emulator
Emulator
In computing, an emulator is hardware or software or both that duplicates the functions of a first computer system in a different second computer system, so that the behavior of the second system closely resembles the behavior of the first system...
or debugger
Debugger
A debugger or debugging tool is a computer program that is used to test and debug other programs . The code to be examined might alternatively be running on an instruction set simulator , a technique that allows great power in its ability to halt when specific conditions are encountered but which...
.