To My Readers



If this is the first time you're visiting my blog, thank you. Whether you're interested or just curious to find out about PCB reverse engineering (PCB-RE), I hope you'll find something useful here.

This blog contains many snippets of the content in my books to provide a more detailed overall sampling for my would-be readers to be better informed before making the purchase. Of course, the book contains more photos and nice illustrations, as evidence from its cover page. Hopefully, this online trailer version will whet your appetite enough to want to get a copy for yourself.

Top Review

I started doing component level repair of electronics with (and without) schematics more than 40 years ago, which activity often involves reverse-engineering of printed circuit boards. Although over the years my technical interests have shifted into particle beam instrumentation, electron microscopy, and focused ion beam technology fields, till this day——and more often than not——PCB repairs have returned multiple multi-million-dollar accelerators, FIB, and SEM instruments back to operation, delivering great satisfaction and some profit.

Many of the methods described by Keng Tiong in great details are similar to the approaches I've developed, but some of the techniques are different, and as effective and useful as efficient and practical. Systematic approach and collection of useful information presented in his books are not only invaluable for a novice approaching PCB-level reverse engineering, but also very interesting reading and hands-on reference for professionals.

Focus on reverse engineering instead of original design provides unique perspective into workings of electronics, and in my opinion books by Keng Tiong (I've got all three of them) are must-read for anybody trying to develop good understanding of electronics——together with writings by Paul Horowitz and Winfield Hill, Phil Hobbs, Jim Williams, Bob Pease, Howard Johnson and Martin Graham, Sam Goldwasser, and other world's top electronics experts.

Valery Ray
Particle Beam Systems Technologist

Thursday, January 19, 2023

Archeological Findings

Writing engineering stuff can sometime feel like doing archeological work. While researching a bit on the history of JTAG, I found out that soon after the IEEE 1149.1-1990 standard was formulated, Intel released its first processor, the 80486DX2, with JTAG implementation and the chip industry quickly adopted the standard and follow suit.

This prompted me to recall an in-circuit project for which I developed a test routine for the i486DX2 CPU back in 1996. It was also my first encounter with JTAG which gave me an alternative way of testing a processor chip without going through the arduous traditional coding process. And I'm happy I managed to dig it out from a pile of past archives and showcase it as an example in Chapter 9:

I'm sure my readers will benefit greatly how boundary scan works by studying the easy to follow test codes in high-level language syntax. It did, however, took me quite a while to understand and figure out the process laid out in the CPU's handbook (I've included the 12-page section on boundary scan test as an appendix).

Of course, newer processors and programmable array chips are much more complex. Thankfully, you don't have to do it the manual way like I did, because JTAG hardware and software tools are available with a comprehensive library of chip manufacturers supplied BSDL files now make it a breeze to test any JTAG-enabled chip on the market, better still, PCBs designed with daisy-chained JTAG devices. This too, will be covered.

That's all for now.

 

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