ICs will be marked with one or more of the following:
- manufacturer's logo
version numbers (eg ROMs, EEPROMs, CPUs with embedded code)
country of manufacture
Date codes are most often in YWW, YYWW, WWYY, or WWY format, where W = work week and Y = year of manufacture. Sometimes the manufacturers will use more cryptic coding, especially for small devices.
Whatever the format, you can often get some clues from the markings on the other ICs. Comparisons with similar PCBs can often be useful, especially when identifying date codes. Often the only difference between two identical ICs will be in their dates of manufacture.
A good source for comparisons with other PCBs is Google Images, eg ...
http://images.google.com/images?q=reals ... o&tbm=isch
In the attached photo clips there is a small component near the bottom right corner of the Marvell controller. Its external support components (2 capacitors plus 1 resistor) suggest that it may be crystal.
If we examine the MCUs, we can see the Marvell logo and the "88SS9174-BLD2" part number.
"TW" suggests that the parts were made in Taiwan.
The first 4 digits on the third line appear to be a YYWW date code.
Code: Select all
MCU date code Crystal marking
YYWW D25 + Y + W
A comparison of the two sets of markings suggests that "D25" may be an abbreviated part number or part code for a 25MHz crystal.
The "1" and "0" probably tells us that the parts were manufactured in 2011 and 2010, respectively.
The last character (M, L, A) is probably the work week.