Until recently, the bandwagon for in-system and in-line programming of flash memories was gathering momentum, but then it suddenly slowed, a victim of the growing capacity of memory devices and more data to program. Unfortunately, while this was happening, the old legacy programming methods in manufacturing weren’t keeping pace with new innovations. Consequently, the time it took to program memory in-system (with the devices soldered to a circuit board) steadily grew until its place on the manufacturing line was threatened. Manufacturing’s beat rate couldn’t be sacrificed for in-system programming (ISP), could it?
Finally, the bandwagon is picking up steam again and in-line ISP is making a comeback. New methods have emerged which can reduce programming times dramatically. In addition, certain distributed programming methods can load multiple circuit boards with multiple flash devices in parallel, increasing ISP speeds by orders of magnitude.
In truth, some of the old technologies that enabled in-line ISP haven’t been totally discarded, only adapted with a few shots of innovation. By and large, boundary scan (JTAG) has always provided access to the flash memory devices for ISP and that’s still the case. Only now some boundary-scan tools, such as ScanWorks, have evolved into a distributed architecture whereby some of the tool’s intelligence has migrated into interfaces pods so that part of the programming application can be distributed from the personal computer where ScanWorks is operating into interface pods. This means that more than one controller can be configured in ScanWorks so that multiple devices on multiple circuit boards can be programmed at the same time.
Another innovation that’s speeding up in-line ISP involves the temporary insertion of a programming engine into an on-board FPGA to drive the process. The bottom line is that all it takes is one boundary-scan station like ScanWorks on the manufacturing line to speed up the whole ISP process tremendously. Plus, the boundary-scan station is available to perform other structural, electrical and functional tests as well.
Of course, there’s more to it than this, but don’t worry; it’s all explained in an easy-to-read eBook. You can download it for free here.