This article introduces four types of JTAG data registers, namely: Boundary Scan Register (BSR) Bypass Register (BR) Device ID Register User Data Register(s) Before discussing the boundary scan register, it’s important to first understand why we need a boundary scan register. Figure 1: Schematic diagram of three chips on a PCB and their interconnections Assume … Read more
Welcome FPGA engineers to join the official WeChat technical group Clickthe blue textto follow our FPGA home – the best and largest pure FPGA engineer community in China 01 Introduction to JTAG JTAG (Joint Test Action Group) is an interface, and a group called the JTAG group was established for this interface in 1985. In … Read more
He is the “Little Horse” mentioned by TK at the GeekPwn conference in 2015, another alchemist who intruded into the security circle (originally a chemistry major) – HyperChem. After a few years of experience in software unpacking, he is currently focusing on embedded security and firmware reverse engineering. This researcher from Tencent Security’s Xuanwu Lab, … Read more
Author: Hcamael@Zhidao Chuangyu 404 Laboratory Date: October 21, 2019 Recently, while working on a router, I accidentally bricked the CFE and discovered that I could recover it through JTAG, so I did some research on JTAG. Initially, I only wanted to recover the brick, without any intention of deep research. Brick Recovery Attempt A Singapore … Read more
Follow our public account for timely updates on new articles. Introduction: Engineers engaged in hardware, embedded systems, or chip-related fields are likely familiar with JTAG. JTAG primarily has three main uses: Testing and Diagnosis: Initially, the main purpose of JTAG was for testing and diagnosing integrated circuits, used to detect and repair defects in the … Read more
Wu Jianying Microcontroller Development Board Address Shop:【Wu Jianying’s Shop】 Address:【https://item.taobao.com/item.htm?_u=ukgdp5a7629&id=524088004171】 This article contains two parts: 1) Continuing the discussion on the TI DSP connection issues; 2) Briefly mentioning the Xilinx FPGA JTAG connection issues. 1. Why Can’t the TI DSP Connect? Half a year ago, I published a blog post titled “Why Can’t the DSP … Read more
01 JTAG (Joint Test Action Group) is an international standard testing protocol (IEEE 1149.1 compliant) primarily used for internal chip testing. Most advanced devices now support the JTAG protocol, such as DSPs and FPGAs. The standard JTAG interface consists of four lines: TMS (Test Mode Select), TCK (Test Clock Input), TDI (Test Data Input), and … Read more
Introduction to JTAG JTAG (Joint Test Action Group) is an international standard testing protocol (IEEE 1149.1 compliant), primarily used for internal testing of chips. Most advanced devices today support the JTAG protocol, such as DSPs and FPGAs. The standard JTAG interface consists of 4 lines: TMS, TCK, TDI, and TDO, which correspond to mode selection, … Read more
Debugging chips relies heavily on the JTAG interface. Downloading and debugging programs must be accomplished through the JTAG interface. Today, I learned some basic principles and working processes of the JTAG interface, and I will summarize them briefly. The JTAG interface is an international standard testing protocol, originally initiated by several electronic device manufacturers who … Read more
Interface Name: JTAG Full English Name: Joint Test Action Group Chinese: 联合测试工作组 Standard Number: IEEE1149.1-1990/IEEE1149.1a-1993 Standard Maintenance: IEEE Current Specification: www.IEEE.org Latest Version: IEEE1149.1-2013 Standard Test Access Port and Boundary-Scan Architecture Effective Date: 2013 Next Version: TBD Description: JTAG is an international standard testing protocol (IEEE 1149.1 compatible), primarily used for internal testing of chips. … Read more