Embedded System Access - New Dimensions in Test Access
The change to multidimensional access started in the late 1990s. The upcoming era of Embedded System Access (ESA) will increasingly replace “old” test methods such as In-Circuit Test (ICT) and Flying Probe (FPT).
The strategy of invasive probe access cannot be utilized any longer for modern system assemblies equipped with Ball Grid Arrays (BGA) and Chip Size Packaging (CSP).
The Boundary Scan standard IEEE 1149.1 has been the foundation stone for Embedded System Access, as early as 1990. Boundary Scan (BST) replaces the mechanic access (needle probes) by an electric access (Silicon Pins), testing directly within the circuitry.
Embedded System Access Technologies and its Features
|Type of Test||structural||functional||open*||functional|
|Test speed||static||dynamic||open*||real time|
|Access via||Boundary Scan IC||Processor||IJTAG IC||Processor|
* depends on implementation