Introduction to JTAG Interface in Embedded C Development

1. Definition:

– JTAG (Joint Test Action Group) is a standard for testing and debugging integrated circuits, widely used in embedded systems development.

2. Purpose:

– To debug, test, and program embedded systems, allowing developers to inspect and manipulate the internal state of the processor.

3. Components:

– The Test Access Port (TAP) controller manages access to the JTAG interface.

4. Key Features:

– Supports boundary scan testing for interconnect checks.

– Enables in-system programming for firmware updates.

– Widely used for real-time debugging without interrupting operation.

5. JTAG Pins:

– TCK (Test Clock), TMS (Test Mode Select), TDI (Test Data Input), TDO (Test Data Output).

6. JTAG Debugger and Probe:

– The JTAG debugger connects to JTAG for debugging.

– The JTAG probe is the connector or cable that links the JTAG debugger to the target system.

7. JTAG Boundary Scan:

– Uses a shift register method to detect interconnect faults on PCBs.

8. JTAG Commands:

– Commands sent through JTAG control the TAP controller to enter debug mode or perform operations such as reading memory.

9. System Debugging:

– OpenOCD is an example of an open-source tool that supports system programming and debugging using JTAG.

10. Common JTAG-Compatible Microcontrollers:

– ARM Cortex-M series microcontrollers typically support JTAG for debugging and programming.

Translator’s note:SEGGER is a well-known supplier of JTAG debugging and development tools with a rich product line.Other JTAG tools include XJTAG, iSystem, etc.

The article comes from social networks, and the author: Sagar Kamjariya is an engineer at a technology service company in India, passionate about FreeRTOS and skilled in device drivers, automotive software, AutoSAR, and CAN bus technology.