White Horse Laboratories digital component testing
Digital components include all those parts that are specifically designed to store and interact with digital programs (sequences of 0’s and 1’s). These products include MCU (micro-control unit), memory and one-time-programmable (OTP) devices.
The most effective way for testing these components is to utilize the program code designed by the component manufacturer. With these programs, we conduct PC-based testing for read and write capability, blanks and blocks on programmable devices, erase programs already loaded, and verify the program identification code for the device.
These are the core functions of these devices so this method of testing is comprehensive. Counterfeit devices, previously used (OTP are useless after first-time program is loaded) and misrepresented (similar, but not same, function) will all be identified using this test method. We can even load programming if it is required!
Combined with a physical inspection, this is a proven method for determining form, fit, and function quality on the components. Of course, the variety of packages and devices is limitless – new products are developed daily and each is unique. White Horse has an inventory of over 35,000 programs from 194 component manufacturers!
With a minimum order of USD110.00 for line set-up, test pricing on these devices is USD0.33 per piece. Lead-time is approximately two days, depending on the number of pieces to be tested and current loading at the time of receipt. Prices for the test fixture for each device vary widely depending on the package style and pin count. Non-BGA devices with a pin count lower than 80 range between USD70 and USD265, and we have many fixtures already developed and in stock. BGA devices and pin counts higher than 80 have prices of USD320 and up. Your Customer Service representative will provide set-up pricing, if applicable, with your quotation.
Digital programmers take advantage of standardized serial ports to program ICs. Some devices like Microprocessors, Field-Programmable, Gate Arrays (FPGA) and Complex Programmable Logic Devices (CPLD) support JTAG access. JTAG was originally developed for debugging of populated circuit boards but was later incorporated to IC in response to the continuing increase in device pin count and functionality. JTAG (Joint Test Action Group) is the common name for what was later standardized as the IEEE 1149.1 (Standard Test Access Port and Boundary-Scan Architecture). The JTAG ports are five device pins that allow access to internal scan lines (known as Boundary Scan Chain). They are assigned as:
1. TDI (Test Data In)
2. TDO (Test Data Out)
3. TCK (Test Clock)
4. TMS (Test Mode Select)
5. TRST (Test Reset) – optional and may not exist in every JTAG capable device
To create a functional test for a JTAG capable device, the engineer will design an application (such as running lights on a series of LEDs) then develop hardware and software program to carry out the design. During program loading, the JTAG ID Code can be read along with the device part number. If the program did not load successfully, the device may not be in good condition. After successful loading, the actual device performance is monitored wherein logic blocks (LUT, CLB, Memory, PLL, I/O, etc.) that were utilized are checked for correct functionality.
In effect, White Horse’s JTAG test is a better test than DPT alone since not only programmability is checked but also functionality. Yet, it is ideal for high pin count devices that cannot be supported by universal programmers.