Analysis and Solutions for Keil5 Debugger Connection Issues

# 1. Basic Principles of Keil5 Debugger

Keil5 Debugger is a powerful tool for debugging embedded systems based on ARM cores. It connects to the target board via JTAG (Joint Test Action Group) or SWD (Serial Wire Debug) interfaces, allowing users to step through the program execution, set breakpoints, inspect variables and register values, and more. The debugger operates based on a hardware component known as the Debug Access Port (DAP), which is responsible for transmitting debug commands from the host to the target board and returning the status information of the target board.

# ***mon Connection Issues and Diagnostics

### 2.1 Analysis of Connection Failure Causes

#### 2.1.1 Hardware Issues

- **Cable Connection Problems:** Check if the debug cable is securely connected to both the target board and the host, ensuring no loose or broken connections.
- **Insufficient Power Supply Voltage:** Confirm that the target board's power supply voltage meets requirements, as insufficient voltage can cause the debugger to malfunction.
- **Target Board Failure:** Inspect the target board for damage or faults, such as burnt chips or circuit board breaks.

#### 2.1.2 Software Issues

- **Incompatible Keil5 Versions:** Ensure the Keil5 version is compatible with the target board firmware version. Incompatible versions can cause connection failures.
- **Debugger Driver Not Installed:** Check if the correct debugger driver has been installed, as the lack of a driver can prevent communication between the debugger and the host.
- **Target Board Firmware Errors:** Corrupted or incorrect target board firmware can prevent the debugger from connecting.

### 2.2 Diagnostic Tools and Methods

#### 2.2.1 Keil5 Log Analysis

Keil5 log files record detailed information about the debugger connection process. Analyzing the log files can identify the causes of connection failures.

**Steps:**

1. Open Keil5 and select "View" > "Debug Log."
2. Attempt to connect to the target board.
3. Check the log file for error messages or warnings.

#### 2.2.2 Target Board Status Check

Checking the target board status can help to rule out hardware issues.

**Steps:**

1. Use a multimeter to measure the power supply voltage of the target board.
2. Check the indicators or LEDs on the target board to confirm they are functioning properly.
3. If possible, use an oscilloscope to inspect the clock signal on the JTAG/SWD pins.

# 3. Practical Solutions for Debugger Connections

### 3.1 Hardware Connection Checks and Repairs

#### 3.1.1 Cable Connection Confirmation

- Check if the JTAG/SWD connection cables are correctly connected to the target board and debugger.
- Ensure that the connection cables are not loose or damaged.
- Test with other connection cables if possible.

#### 3.1.2 Power Supply Voltage Check

- Confirm that the target board is correctly powered.
- Check if the power supply voltage meets the target board's requirements.
- Use a multimeter to measure the power supply voltage on the target board.

### 3.2 Software Settings Optimization

#### 3.2.1 Keil5 Options Configuration

- Open Keil5 and go to the "Options for Target" dialog box.
- In the "Debug" tab, check the following settings:
- **"Use" Option:** Select the correct debugger type (JTAG/SWD).
- **"Connection" Option:** Select the correct connection method (SWD/JTAG).
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