4.3. Data file format

JTAG declarations files are located in directory "data". The files contains common part specific JTAG information in parseable form, e.g. list of the JTAG commands, boundary scan register, list of JTAG registers, etc.

Syntax of the JTAG declaration file is defined in the following subsections.

4.3.1. General rules

JTAG declaration file is text file which consists of lines. Empty lines are ignored. Text after first "#" on the line to the end of line is ignored. This is useful for comments. All other lines are significant.

Each significant line consists of tokens separated by whitespace. Whitespace could be spaces and/or tabs.

4.3.2. Signal Definition

Signal definition line consists of word "signal" followed by whitespace and signal name (without spaces in the name). Rest of the line should contain whitespace separated list of pins of the part. This list is currently not used for any purpose in JTAG Tools. It is intended for future use.

4.3.3. Manufacturers List

The data/MANUFACTURERS file is used to locate the manufacturer of a specific device found in the JTAG chain. If you get the error Unknown manufacturer when attempting the detect command, this is the file you need to update.

See the JEDEC document for more information: JEDEC Solid State Technology Association, "Standard Manufacturer's Identification Code", September 2001, Order Number: JEP106-K

4.3.3.1. Format

The first token is a bit string that matches bits 11-1 of the device's IDCODE. We omit bit 0 because it should always be 1 (per the JEDEC standard).

The second token is the name of the directory under data/ to search for specific part information.

The rest of the line is the human readable form of the manufacturer's name.

For example, we find this in data/MANUFACTURERS:

00001100101   analog          Analog Devices, Inc.

The manufacturer's IDCODE is 000011001011 (notice the last bit is stripped), more part information can be found under data/analog/, and the human friendly name is Analog Devices, Inc..

4.3.4. Parts List

Every manufacturer subdirectory needs a PARTS file. This is used to look up further information about a part such as the stepping and signal list. If you get the error Unknown part when attempting the detect command, this is the file you need to update.

4.3.4.1. Format

The first token is a bit string that matches bits 27-12 of the device's IDCODE.

The second token is the name of the directory under the manufacturer's data/ directory to search for specific part information.

The rest of the line is the human readable form of the part's name.

For example, we find this in data/analog/PARTS:

0010011111001000      bf537                   BF537

The part's IDCODE is 0010011111001000, more part information can be found under data/analog/bf537/, and the human friendly name is BF537.

4.3.5. Stepping List

Every part subdirectory needs a STEPPINGS file. This is used to find the file that contains information like the signals list. If you get the error Unknown stepping when attempting the detect command, this is the file you need to update.

4.3.5.1. Format

The first token is a bit string that matches bits 31-28 of the device's IDCODE.

The second token is the name of the file to load that contains information like the signal list, extra instructions/registers, etc… This file should be placed alongside the STEPPINGS file in the part-specific subdirectory.

The rest of the line is the human readable form of the part stepping's name.

For example, we find this in data/analog/bf537/STEPPINGS:

0010  bf537           2

The part's stepping is 0010, signal information can be found in the file data/analog/bf537/bf537, and the human friendly stepping name is 2.