# Example USB-based JTAG interface

Example of a USB-based JTAG interface in the:
`${prefix}/share/doc/geda-gaf/examples/gTAG`
directory, where `${prefix}` is the installation prefix for gEDA on your system (usually `/usr` or `/usr/local`).

    		gTAG - 	USB to JTAG interface
    		============================

    This is the README file for the schematic of gTAG.

    Short description
    -----------------
    gTAG is an interface to connect your USB port of computer to talk
    to your circuits which talks JTAG.

    Copyright
    ---------
    These schematics is (C) by Stefan Petersen (spe@stacken.kth.se) and
    released under GPL (see the attached file COPYING). GPL is mainly
    written for software, ie intellectual property in electronic form.
    By making this schematic an intellectual property in electronic
    form gTAG schematics can be covered by GPL.

    How?
    ----
    These schematics are made with gschem and netlists are then generated
    with gnetlist. Both gschem and gnetlist are part of gEDA
    (http://www.geda-project.org).

    Files
    -----
    The distribution of the schematics of gTAG should consist of:
    * README - this file.
    * COPYING - GPL copyright notice.
    * crdist.sh - shell script used to generate the tar.gz.
    * ChangeLog - tries to scribble down what has changed between versions.
    * Four component symbols:
      - 7414-1.sym - Original 7414 from gschem without power attributes.
      - max882.sym - 5-to-3.3 V converter.
      - cy7c64603-52nc.sym - USB microcontroller from Cypress.
      - sn75240pw.sym - Surge supressor for USB
      - copyleft.sym - Symbol with GPL text for all schematics.
    * Five schematics with four symbols:
      - gTAG.sch.sch - Toplevel schematic for gTAG
      - gTAG-jtagio.[sym/sch]
      - gTAG-ucont.[sym/sch]
      - gTAG-consio.[sym/sch]
      - gTAG-psu.[sym/sch]
    * gEDA rc-files for this project:
      - commonrc - contains common declarations for both gschem and gnetlist
      - gnetlistrc - gnetlist specific and and calls commonrc
      - gschemrc   - gschem specific and and calls commonrc