CMSIS-DAP is an interface defined by ARM that provides a standardized way to access the Coresight Debug Access Port (DAP) of an ARM Cortex microcontroller via USB. For more information on CMSIS-DAP, please visit the ARM/MBED CMSIS-DAP site.
Support for CMSIS-DAP in LPCXpresso
A variety of debug probes are now available that implement a CMSIS-DAP interface, either standalone or built into development boards. Connection to such probes is supported from LPCXpresso IDE v6 onwards.
Only specific CMSIS-DAP enabled probes have been tested with LPCXpresso. At the time of writing (LPCXpresso IDE v8.2.2), these include:
- LPC-Link2, LPCXpresso V2/V3 softloaded with CMSIS-DAP debug firmware in RAM (the default from LPCXpresso IDE v7.8 onwards)
- LPC-Link2, LPCXpresso V2/V3 pre-programmed with LPC-Link2 CMSIS-DAP firmware
- LPCXpresso MAX boards
- NOTE - If running on Windows, you will need to install the mbed Windows serial port driver in order for the LPCXpresso-MAX's CMSIS-DAP debug link to be visible to LPCXpresso.
- LPCXpresso CD boards
- Keil ULINK-ME, programmed with CMSIS-DAP firmware
- Keil ULINK2 programmed with CMSIS-DAP firmware
Other CMSIS-DAP probes may also work. If you encountered a CMSIS-DAP probe that is not detected or does not work with LPCXpresso IDE, then please submit details via the LPCXpresso IDE Community Forum.
LPCXpresso 7.7.2 and later
From version LPCXpresso 7.7.2, the CMSIS-DAP support layer allows the use of JTAG as well as SWD connections. This means, for example, that LPC43xx parts can now be debugged using a CMSIS-DAP probe without needing to reconfigure the launch configuration to use SWD.However it should be noted that:
- Some CMSIS-DAP probe implementations do not support JTAG
- Some MCU’s (in particular Cortex-M0/M0+ based parts) do not support JTAG
LPCXpresso 7.6.2 and earlier
In earlier releases of LPCXpresso IDE, the CMSIS-DAP support layer did not allow the use of JTAG connections.
If you tried to connect via JTAG, then you would see an error of the form "RedlinkAPI: Unsupported with current settings".
Generally this should not be an issue, as for most targets LPCXpresso will by default connect via SWD.