Test Framework for On-Die CPU

Abstract

This thesis presents the development and implementation of a self-contained on-chip test framework designed to validate analog-to-digital (ADC) and digital-to-analog (DAC) converters integrated within an Application-Specific Integrated Circuit (ASIC). Utilizing the embedded ARM Cortex-M7 processor within the ASIC, the test framework eliminates reliance on external instruments by internally performing all necessary validation processes, including configuration, sampling, data conversion, and detailed post-processing. Through sophisticated digital signal processing techniques such as Fast Fourier Transform (FFT) and power spectrum estimation, the framework assesses signal integrity and system performance in real-time. This approach significantly reduces test complexity and resource usage and enhances scalability for mass production environments, demonstrating notable advancements in embedded validation methodologies for high-performance integrated systems. Initially started as a validation framework, this work has evolved into a fully pledged embedded firmware suitable for any further on-chip development.

Popular Abstract

Every day, billions of electronic devices from smartphones and smartwatches to medical scanners and autonomous vehicles depend on tiny chips that convert real world signals like sound, light, and temperature into digital data and back again. Modern electronic devices, especially those involved in wireless communication, rely heavily on the accurate and efficient conversion of real world signals into digital data and vice versa. These conversions are managed by highly specialized chips known as Application Specific Integrated Circuits (ASICs), which often include analog-to-digital converters (ADCs) and digital-to-analog converters (DACs). Ensuring that these converters function correctly is crucial for the overall reliability of the devices.
Traditionally, such validation has required complex and expensive lab equipment, involving hours of manual effort and external testing. In this thesis, we present a self contained, on-chip test framework/firmware that brings the entire validation process directly onto the ASIC itself. By using the embedded ARM Cortex-M7 processor already present within the ASIC, our framework eliminates the need for external oscilloscopes, signal generators, and computers. Instead, the chip configures its own ADCs and DACs, generates and samples test signals, and performs all necessary data conversion and post processing internally. This embedded approach transforms each ASIC into its own miniature test factory.
At the heart of our solution are advanced digital signal processing techniques most notably Fast Fourier Transform (FFT) and power spectrum estimation, which allow the processor to assess signal integrity, distortion levels, and overall system performance in real time. As soon as the chip boots up, it runs its built-in firmware to execute comprehensive tests, immediately flagging any anomalies. This real-time feedback accelerates development cycles, catches faults early, and dramatically reduces the complexity and cost of validation. By integrating testing capabilities directly into the hardware, our framework offers significant benefits for mass production. Manufacturers can deploy the same on-chip firmware across thousands of units, enabling parallel validation without investing in large scale test rigs or extensive manual labor. Moreover, what began as a dedicated converter validation tool has evolved into a flexible embedded firmware platform, ready to support further on-chip developments. Looking forward, this on-chip testing paradigm promises to revolutionize how high performance integrated systems are brought to market. Future extensions may include validating radio frequency modules, power management circuits, and even incorporating machine learning algorithms for predictive diagnostics. By making each chip its own tester, we pave the way for smarter, more efficient, and highly scalable validation methodologies helping ensure that the next generation of electronics meets the highest standards of reliability and performance.

• author: Eriksholm, Tam and Gomeshlou, Mehran
• supervisor: Per Andersson
• organization: Department of Electrical and Information Technology
• course: EITM02 20251
• year: 2025
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• report number: LU/LTH-EIT 2025-1060
• language: English
• id: 9196347
• date added to LUP: 2025-06-13 07:58:50
• date last changed: 2025-06-13 07:58:50