Using Programming Pods At The In-Circuit Test Stage

Nowadays using programming pods are commonly accepted and widely used in manufacturing, especially when a new product is introduced and the firmware is in the early development stages.
After the completion of all visual and structure tests, the board is ready for full functional test. The in-circuit test station is the best point for programming an electronic board for the following reasons:
  • All the tests are performed
  • There is easy access to programming header
  • Programming pods can be installed inside an ICT fixture
  • The next test station is usually the functional test station
The difficulties of performing device programming at the in-circuit level are:
  • When the boards are panelized
  • There is no easy access to push buttons and display
  • The process needs to be automated with minimal, or no operator intervention
  • Programming pods need to be loaded with new firmware from time to time
In a recent project, a customer asked to program a panelized board. Each board has two different programmable devices. Our approach was to use two programming pods (P&E Micro Cyclone Pro programming adapter) with multiplexers. This project presented all four of the difficulties listed above.
Bed of nails test fixture
In order to overcome the panelized board issue, we decided to use two multiplexer boards which were being controlled through the in-circuit test program. Since there were six boards in each panel, each multiplexer was responsible for programming three boards.
mulitplexer_schematic
Cyclone Pro programmers are very easy to use. As soon as the firmware is loaded, the user only needs to press the “START” button and monitor “SUCCESS” and “ERROR” LEDs. In order to automate the process, we decided to “wire” the above mentioned control lines (START button, SUCCESS and ERROR LEDs) to the ICT machine, so controlling the process would be through the ICT program and the operator will have no intervention. After sending “START” command, the test program monitors two LEDs for the result. If “SUCCESS” LED turns on, the test program will send a “Programming PASS” message to the screen, otherwise the result is a fail and the screen will show “Programming FAIL”.
ICT Fixture With USB PortIn order to be able to upload the latest firmware into the programming pods, the test fixture incorporated 2 USB connectors, each of which was connected to one of the programming pods. This allows a test engineer to quickly and easily upload a newly released firmware through the USB bus to the pods.
A general overview of the pods and multiplexers inside the test fixture is shown here:
In-circuit test fixture programming pods