Hybrid based Self-Test Solution for Embedded System on Chip

Abstract

Microcontrollers have become a widely accepted architecture for highly complex embedded systems on a single chip (SoC). It consists of deeply embedded heterogeneous components with poor accessibility makes their testing process a difficult task using hardware based self-test (HBST). Software-based self-test (SBST) is considered to be a promising testing technology for these systems. Almost every SoC contains at least one embedded processor, SBST utilize this processor for test pattern generation (TPG) and test response compaction (TRC) based on its instruction set, then test response will be unloaded and evaluated using external automatic test equipment (ATE). In this paper, SBST strategy disadvantages in microcontroller testing will be identified. Then, a new testing approach that combines both the HBST and the SBST, called hybrid-based self-test (HYBST) will be introduced. Based on a divide-and-conquer approach, HYBST identify microcontroller's components and their corresponding component operations. Feasibility and effectiveness of HYBST and SBST methodologies will be assessed by applying them to a Microchip ® PIC16F877A and PIC18F452 in terms of memory usage, time consumption and number of tested modules found in microcontrollers.

New Hybrid-Based Self-Test Strategy for Faulty Modules of Complex Microcontroller Systems

“…Most of them fall into two main categories: in-circuit testing (ICT) and functional testing [1][2][3][4][5]. The ICT requires a costly special kind of the test fixture (bed of nails) [2]- [3], [6]. The functional tester verifies that the CUT board performs the functions it was designed for.…”

“…Microcontrollers are considered an important part of the electronic system. The complexity of microcontrollers with poor accessibility makes their test process a difficult task using external automatic test equipment (ATE) [2]- [3], [6]. Therefore, empowering chip to test itself looks the suitable solution for the microcontroller testing.…”

“…Therefore, empowering chip to test itself looks the suitable solution for the microcontroller testing. The built-in self-test (BIST), considered a mechanism of the hardware based self-test (HBST), provides significant advantages not only for processor module but also for other peripherals found in the microcontroller [6]. [8]- [9].…”

“…Signature analysis is a TRC technique that detects errors in stream data of bits, caused by hardware faults. It compacts the test response for each output node of the CUT board into a signature [4], [6], [9]- [11]. After all required input test patterns are applied, the reference (good) signature is generated.…”

“…The authors in this paper implemented the SBST strategy to test two different families of the PIC microcontrollers (PIC16F87X -PIC18F4X2) [6], [31]. It was found that the SBST needs large space of memory for the instruction set code that emulates the TPG, the TRC, and the test controller to realize self-test operations.…”