4 phillip stanley-marbell
1.06 mm package for the ADXL362), and much more. Typically, all of this in-
formation is contained on the first page„ followed by a block diagram, and
further details as detailed in Section
B.2 below.
A reference manual, user guide, or user manual on the other hand typically
contains a detailed description of the (digital) behavior of an integrated cir-
cuit and is most commonly a separate document in the case of microcon-
trollers and microprocessors. For example, for the NXP/Freescale KL03
microcontroller family, there are separate datasheets (e.g., Kinetis KL03 32
KB Flash 48 MHz Cortex-M0+ Based Microcontroller
2
) and a separate reference
2
Freescale Semiconductor
2014a.
manual (KL03 Sub-Family Reference Manual
3
).
3
Freescale Semiconductor
2014b.
Both datasheets and reference manuals will typically contain a revision
number or date, and it essential to have copies of the newest version (which
might include fixes of errors) as well as copies of older versions (to under-
stand why you may have made a given design decision based on erroneous
information in a datasheet). Both will also typically contain a section (typ-
ically at the end of the document) with a history of changes made to the
current and previous versions of the document. Typically (but not always),
the different versions of a manual are given different filenames by the man-
ufacturer, so it is easy to keep the different versions without overwriting old
versions upon downloading a new one. For this reason, it is advisable to
only download datasheets directly from the manufacturer. There are vari-
ous web pages online that bill themselves as one-stop shops or repositories
for datasheets. These sites have no incentive to abide by these guidelines,
and are usually setup as a way to attract advertising. Given the significant
amounts of time that you could waste due to incorrect documentation, and
given the possibility of physical hard that can result from embedded systems,
it is wise to get datasheets directly from a device’s manufacturer.
In addition to errors in documentation, there might be design errors or
implementation errors in actual integrated circuits themselves. Most manu-
facturers issue a separate document, the errata, to detail these problems and
to give work-arounds if there are any.
The quality of datasheets varies widely across manufacturers. For the
last decade or so, datasheets for displays have by and large been the most
difficult to decipher (to put it politely). Examples of companies with high
quality datasheets include Texas Instruments (TI) and Analog Devices (ADI).
B.2 The Anatomy of a Typical Datasheet
A typical datasheet consists of eight parts:
➊ The document revision number. This is not really a section on its own but
is important enough to call explicit attention to it here.