pylink

The JLink class is the primary interface for interacting with the J-Link C SDK. It provides a Pythonic wrapper around native SDK functions.

Note that certain methods require specific preconditions, such as having a target device connected or an emulator connected. If these conditions are not met, the library will raise an exception rather than returning error codes.

The J-Link supports multiple communication methods to interact with a target, including Serial Wire Debug (SWD), Serial Wire Output (SWO), Memory, Coresight, and Registers.

To facilitate communication, pylink provides protocol-specific modules. While all protocol methods require an existing JLink instance to function, the protocol modules handle the specific housekeeping and low-level communication logic required for each method automatically.

To control a J-Link using Python, import the pylink module, instantiate a JLink object, and use the open method with the device's serial number. You can then access properties like product_name to verify the connection.

import pylink

jlink = pylink.JLink()
jlink.open(serial_no=123456789)
print(jlink.product_name)

After opening the emulator, use .connect(device_name) to connect to a specific target device (e.g., 'MKxxxxxxxxxx7'). Once connected, you can query device information such as .core_id() and .device_family(). Use .target_connected() to confirm the target is successfully attached.

jlink.connect('MKxxxxxxxxxx7')
print(jlink.core_id())
print(jlink.device_family())
print(jlink.target_connected()) # Returns True if target is connected

On Windows, you can make JLinkARM.dll available to PyLink using one of these methods:

1. Copy the DLL: Place JLinkARM.dll in the current execution directory, the Windows system directory, or the Windows directory.
2. Update PATH: Add the SEGGER J-Link installation directory to your %PATH% environment variable.

To install the development version (master branch), clone the repository and run setup.py. For a more stable installation, it is recommended to check out a specific release branch before installing.

To install the development branch:

$ python setup.py install

To install from a specific release branch:

$ git checkout release-major.minor
$ python setup.py install

On Linux, you can ensure PyLink finds the J-Link library by using one of these two methods:

Option A: Copy the library file to your libraries directory

cp libjlinkarm.so /usr/local/lib/

Option B: Add SEGGER's J-Link library path to your libraries path

export LD_LIBRARY_PATH=/path/to/SEGGER/JLink:$LD_LIBRARY_PATH

# Option A
cp libjlinkarm.so /usr/local/lib/

# Option B
export LD_LIBRARY_PATH=/path/to/SEGGER/JLink:$LD_LIBRARY_PATH

On macOS, you can ensure PyLink finds the J-Link library by using one of these two methods:

Option A: Copy the library file to your libraries directory

cp libjlinkarm.dylib /usr/local/lib/

Option B: Add SEGGER's J-Link directory to your dynamic libraries path

export DYLD_LIBRARY_PATH=/Applications/SEGGER/JLink:$DYLD_LIBRARY_PATH

# Option A
cp libjlinkarm.dylib /usr/local/lib/

# Option B
export DYLD_LIBRARY_PATH=/Applications/SEGGER/JLink:$DYLD_LIBRARY_PATH