Uwharrie Test Solutions
No Boundary Scan on your Microcontroller?
Firmware Scan Test Process
I have chosen not to patent this test process. Feel free to reproduce this process. I am sharing this with the electronics manufacturing industry for the possibility that I may be commissioned to put it to use. I have already done so with a number of microcontrollers.
The purpose of Firmware Scan is to fill a void in the in-circuit test coverage of most microcontrollers.
Some microcontrollers have Boundary Scan IEEE 1194.1 capability which makes the pin test easy to do. However, most microcontrollers have no pin-test capability embedded in the device. In this case most test engineers will implement a vector-less technique. This adds considerable cost to the ICT fixture, not to mention reliability problems, false-pass, false-fail, etc..
A common design for a high volume product is a PCBA with a microcontroller, some glue logic and/or some analog circuitry. ICT will test everything, quite well, except for the microcontroller. This is the ideal application for Firmware Scan.
Firmware Scan is a test process that uses a firmware driven state machine uploaded to the microcontroller that gives the device a pin-test capability equivalent to Boundary Scan.