Getting Started with the Target Access plugin for IAR Embedded Workbench

The Target Access plugin for the C-SPY Debugger, alongside its SDK, are automatically installed with the IAR Embedded Workbench.

The plugin provides a server that listens to the 9931/UDP port and runs on top of the C-SPY Debugger. Its Target Access SDK provides an API for a third-party client to establish a network connection to the server and, from there, tap into a device target's memory to perform runtime read/write access. The SDK also provides capabilities for a client to monitor hardware ITM events.

sequenceDiagram
autonumber
title C-SPY Target Access Plugin
participant Target Access Client
participant Target Access Server
participant C-SPY Debugger
participant Target Device

note right of Target Access Client: 9931/UDP;
Target Access Client ->> Target Access Server: TargetAccess*();
rect rgb(240, 240, 240)
note right of Target Access Server: Internally processed by C-SPY
Target Access Server ->> C-SPY Debugger: (TargetAccess*());
alt R/W memory
  C-SPY Debugger-->>Target Device: ;
else ITM listener
  C-SPY Debugger-->>Target Device: ;
end
Target Device ->> C-SPY Debugger: (Output/Result);
C-SPY Debugger ->> Target Access Server: (Output/Result);
end
Target Access Server ->> Target Access Client: Output/Result;

This repository contains simple examples of client applications created with the Target Access SDK. They can connect to the server's UDP port, exposed by the Target Access Client DLL.

The Target Access Plugin SDK is installed at C:/path/to/IAR/Embedded/Workbench/arm/src/TargetAccessPlugin.

Note For more information on the SDK API details, refer to the Getting Started Guide for the Target Access Plugin, installed inside the Target Access Plugin documentation folder (C:/path/to/IAR/Embedded/Workbench/arm/src/TargetAccessPlugin/doc/TargetAccessPlugin.pdf).

Example programs

Building the example programs

To build the example programs you will need:

• IAR Embedded Workbench for Arm V9 or later
• Microsoft Visual Studio 2022 or later, installed for C++ Desktop Development

1. Launch "Developer Command Prompt for VS 2022".
2. Clone this repository.
3. Build the examples:

cd cspy-target-access-demo/examples
mkdir build && cd build
cmake .. -DTOOLKIT_DIR="C:/path/to/IAR/Embedded/Workbench/x.xx/arm"
cmake --build . --config Release

Note TOOLKIT_DIR must point to the arm subdirectory in the installation directory of the IAR Embedded Workbench.

Three example programs should be inside the Release directory: mem-reader.exe, mem-writer.exe and itm-logger.exe. Also, a copy of the TargetAccessClientSDK.dll library was automatically placed together with these executables.

Syntax notes

mem-reader <32-bit address>

mem-writer <32-bit address> <32-bit value>

itm-logger

Note The itm-logger example requires an actual hardware target.

Running the memory access example programs

The memory access example programs can be used with the C-SPY Simulator (or adapted to run on hardware).

1. In IAR Embedded Workbench, open the cspy-target-access-demo\target\target.eww workspace.
2. Choose Project → Download and Debug (Ctrl+D).

Note On the Debug Log window, you shall see a message similar to:

Sun Jan 01, 2023 12:00:00: TargetAccessPlugin: Started listening on port 9931

3. Choose View → Live watch and <click to add> buffer and val.
4. In "Developer Command Prompt for VS 2022", execute:

.\Release\mem-reader 0x20001000
.\Release\mem-reader 0x20002000
.\Release\mem-writer 0x20001000 0x1000
.\Release\mem-reader 0x20001000
etc.

Note As you use the mem-writer application to modify the target's variables buffer or val, you shall see their updated values in the C-SPY Live Watch window.

Running the itm-logger example program

For executing the ITM Logger example, you will need to create a new C Project in IAR Embedded Workbench. The program should configure the hardware device target clocks. You will also need a debug probe. For the best experience, we recommend the IAR I-jet.

Note It is assumed that the hardware provides the Instrumentation Trace Macrocell (for example Cortex-M4).

1. Create/Generate a new C project that initializes the desired hardware target. If convenient, use the Code Generator provided by the silicon manufacturer.
2. Add cspy-target-access-demo/target/demo.c to the project.
3. On the created application's main.c file, add extern void demo(void); so you can call demo() from the main() function, similar to what was done in target/main.c.
4. Choose Project → Options (Alt+F7) → Debugger → Plugins and ☑️ Target Access Server.

Note If necessary, set up:

• General Options → Target → Device.
• Debugger → Setup → Driver → I-jet.
• I-jet → Interface → SWD.
• and any other relevant project options.

5. Choose Project → Download and Debug (Ctrl+D).
6. Choose I-jet → SWO Configuration.
7. Select the ITM ports 20 and 21 (23◼️◼️☑️☑️◼️◼️◼️◼️16) and deselect any others.

Note On Cortex-M devices, there are 32 ITM ports (0-31). ITM ports 0-19 are reserved by IAR Embedded Workbench. When creating client applications, make sure they only use the ITM ports 20-31. Using reserved ITM ports from external client applications may result in undefined behavior.

8. Choose Debug → Go (F5).
9. In the "Developer Command Prompt for VS 2022", execute:

.\Release\itm-logger.exe

Output example (click to unfold):

[d47c6888e] ITM port 20: 0000005b (1 byte length)
[d4950f8cb] ITM port 21: 0a3e35ec (4 bytes length)
[d49ca33f3] ITM port 20: 0000006f (1 byte length)
[d4b591c11] ITM port 20: 00000079 (1 byte length)
[d4c90a7ed] ITM port 20: 0000003d (1 byte length)
[d4c91500f] ITM port 21: 0a40b6a4 (4 bytes length)
[d4e8fffe6] ITM port 21: 0a424244 (4 bytes length)
[d4f966a5d] ITM port 21: 0a430c25 (4 bytes length)
[d5136b290] ITM port 21: 0a444de9 (4 bytes length)
[d52387343] ITM port 20: 00000079 (1 byte length)
[d53fd977e] ITM port 20: 000000c9 (1 byte length)
[d5576ae7d] ITM port 20: 00000083 (1 byte length)
[d569365f0] ITM port 20: 000000ab (1 byte length)
[d58422aa1] ITM port 20: 000000a1 (1 byte length)
[d5947373e] ITM port 21: 0a4a8380 (4 bytes length)
[d5aa61e0e] ITM port 20: 00000083 (1 byte length)
[d5c678198] ITM port 21: 0a4cecb4 (4 bytes length)
[d5de70463] ITM port 20: 000000b5 (1 byte length)
[d5f36b798] ITM port 21: 0a4f1a09 (4 bytes length)
[d60b272f0] ITM port 20: 000000d3 (1 byte length)
[d61a267bb] ITM port 20: 00000047 (1 byte length)
[d632a4982] ITM port 20: 000000e7 (1 byte length)
[d6543181e] ITM port 21: 0a53c1f9 (4 bytes length)
[d6562fe4b] ITM port 20: 00000029 (1 byte length)
[d68113ea2] ITM port 21: 0a55eb00 (4 bytes length)
[d68364bbd] ITM port 20: 000000bf (1 byte length)
[d696e5913] ITM port 20: 0000008d (1 byte length)
[d6ac34750] ITM port 20: 00000015 (1 byte length)
[d6af3d321] ITM port 20: 00000001 (1 byte length)
ITM Listener: on Channels: 0xffffffff Buffer capacity: 1000 Buffer size: 0  

Target Access from cspybat

The Target Access Server plugin can also be used from the command line, with cspybat.

Append the following parameter in the project's settings/target.Simulator.general.xcl:

--plugin="C:/path/to/IAR/Embedded/Workbench/common/plugins/TargetAccessServer/TargetAccessServer.dll"

So that the settings/target.Simulator.cspy.bat script will execute cspybat with Target Access support.

Note Use Ctrl-C to terminate the batch job.

Disclaimer

The information in this repository is subject to change without notice and does not represent a commitment on any part of IAR. While the information contained herein is assumed to be accurate, IAR assumes no responsibility for any errors or omissions.

Troubleshooting

If there are technical issues related to the IAR products and you are eligible for support, please get in touch with the IAR support services: https://iar.com/support.