HardwareDebug
From RTEMSWiki
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Hardware Debugging
Embedded processors these days provide hardware assisted debugging. Typically the processor provides an interface which allows an external device the ability to take control of the processor. In the past hardware assisted debugging required an emulator. These were expensive, often difficult and fragile to connect to the target hardware and often limited in numbers in a project making debugging a time share operation. Any newer or faster processor usually required a new emulator. Todays microprocessors implement a range of functions found in emulators in the processor allowing every target the ability to be used for hardware assisted debugging.
Different microprocessors have different ways of the implementing harwdare assisted debugging.
- Freescale Coldfire and M683xx processors use Background Debug Mode (BDM).
- ARM uses JTAG.
- PowerPC MPC5xx and MPC8xx use BDM, while the rest of the PowerPC family uses various kinds of JTAG interfaces.
Coldfire and M683xx BDM
The BDM interface is a synchronous serial bus interface. The physical interface (connector) varies between the M683xx and Coldfire processor yet the way BDM works is similar. BDM is support by an Open Source Project which you can find here http://bdm.sourceforge.net/. The BDM project's software uses a low cost pod that connects between your target hardware. You can use the older parallel port pods that connect to your PC's parallel port or you can use the newer USB pods.
The USB pod is an open source design called the Turbo BDM Light Coldfire (TBLCF) created by Daniel Malik. You can download the design and build yourself [1] or you can obtain a manufactured pod from Axiom Manufacturing [2].
If using a parallel port pod watch you get the correct pod. Different procesor speeds and core voltages require different pods. Newer pods should be able to handle the faster processors and different core voltages.
The latest version of the BDM software use a GDB server program and allows the use of the standard M68K GDB tool provided in the RTEMS binary tools packages.
ARM
Information goes here.
PowerPC
Information goes here.
