Freescale supplies certain development boards with an integrated debug circuit based on Open Source JTAG. This allows the development board to be debugged from the PC via the USB bus without requiring external debug hardware, such as the Cyclone or USB Multilink Universal. The development board also derives its power from the USB Bus.
The Open Source JTAG circuit design (OSJTAG-JM60) is an open source, community driven design. It has been published on Freescale's website, and full documentation can be found in the Community Forums. The latest documentation and firmware can be downloaded from www.pemicro.com/osbdm.
Integration with CodeWarrior is handled via the "Open Source JTAG" connection. P&E has integrated the Open Source JTAG support into the same connection that supports both the USB ColdFire Multilink and the Cyclone . All of the dialogs that affect operation of these hardware interfaces function in the same manner when using OSJTAG (albeit at a lower data rate).
The Open Source JTAG Connection setting permits a connection to Open Source JTAG devices. Open Source JTAG mode lets you debug code, as the firmware is fully resident in the Flash or RAM of the microprocessor. The operation of all modules fully reflects the actual operation of the onboard resources.