Texas Instruments Serial Programming Adapter MSP430 User manual

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Texas Instruments (TI) is a well-known US-based semiconductor manufacturer. TI is perhaps best
known to many as the manufacturer of some of the fanciest scientific calculators in the market. Of the
long list of electronic devices produced by TI, microcontrollers are on the top. TI manufactures some
of the coolest and advanced microcontrollers of the market today. There are several categories of
micros from TI. These include general purpose low power MCUs which mainly comprise of MSP430s,
ARMs like TM4Cs, MSP432s, etc, micros for wireless communications like CC2xxx series, ARM + DSP
micros, DSP-specialized micros like the TMS32xxx series and so on. It will look as if TI is committed
toward mixed signal microcontrollers that are engineered for highly sophisticated industrial
challenges. This issue will cover an insight of value-line MSP430 general purpose micros.
MSP430s are not seen as much as the popular 8051s, PICs and AVRs. In most of the Asian market, for
example, MSP430s are rare when compared to other microcontrollers and even still rare when
compared to other chips produced by TI itself. I don’t know why there is such an imbalance. Perhaps
one big reason is its inclination towards low power consumption and limited resources. Low-power
means that these MCUs are crafted for special low power applications unlike most other micros.
Secondly TI micros are a bit expensive than other micros. Despites these, TI has provided some great
tools for making things simple. You can get your hands on some cool MSP430 chips through some
affordable Launchpad boards and still it worth every penny learning MSP430s. Firstly, it is a family of
ultra-low power high performance 16-bit (16-bit data bus) micros which are unlike the popular 8-bit
platforms. Secondly MSP430s have highly rich internal hardware peripherals that are second to none.
For instance, MSP430s can be operated over a wide voltage and frequency ranges. Another great
feature that is less common in most 8-bit micros is the DMA controller. Fortunately, MSP430s possess
this. Probably it is your first such micro family that is somewhere between 8-bit and 32-bit micros. In
the end, MSP430s will surely give you a taste of absolute American technology and concepts.

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The MSP430 Family
Shown below is the family tree of MSP430 series microcontrollers from TI.
The most common MSP430 micros are the MSP430FR series, MSP430F series, MSP430G series and
the newly introduced MSP432 series.
MSP430FR series micros mainly feature high reliability, high endurance, 10-year data retention non-
volatile FRAM (ferroelectric random-access memory) memories. This series offer 16-bit solutions for
ultra-low-power sensing and system management in areas like smart building management systems,
smart grids, military and industrial designs. They feature the lowest standby power consumption of
about 350 nA with RTC, 100 µA/MHz active power consumption and the unique ability to save and
instantly restore system state right after power failures.
MSP432 series micros are the perfect combinations of MSP430 low-power portfolio with advanced
mixed-signal features and the high-performance processing capabilities of 32-bit ARM M4F engine.
These micros have high measurement precisions and contain high performance peripherals like high
resolution differential ADCs, DMA, IOT connectivity, etc. This series fills the gap between 16-bit
MSP430s and 32-bit ARM architecture and as of this moment this series is the most recent
development in the MSP430 family.
CC430 series is a small series of MSP430s with almost all features one can find in a typical MSP430
micro and embedded sub-GHz radio transceievers. They are well-stuffed true System-on-Chip (SOC)
solutions that remove the necessity of additional off-board wireless solutions.
Yet another tiny series of MSP430 micros include MSP430Cxx and MSP430Lxx micros. These micros
are intended for extreme low voltage (0.9 –1.65V) operations. With just one Nickel Cadmium (NiCd)
battery it is possible to run any micro of this series. They feature low resolution analogue frontends
and low pin counts.

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The only series that is left to be discussed is the general purpose MSP430s series microcontrollers. By
general purpose, it is meant that these micros can be use in almost any scenario. It is this series of
micros that we will be dealing here. The table below summarizes this family:
For now, don’t struggle to understand the abbreviations of this table. You’ll eventually know about
them as we proceed.
Note that there are some other MSP430 devices that are not accounted here. These devices are either
rare or subset of the mentioned families. If you want to know more about MSP430s then you can read
the following Wikipedia article: https://en.wikipedia.org/wiki/TI_MSP430.

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Launchpad Boards and BoosterPacks
Launchpad boards are affordable MSP430 evaluation kits. For just few dollars, you can have your own
Launchpad boards. They are so cheap that an average school-going student can afford one with
his/her own pocket money. However, this cheapness doesn’t compromise quality nor performance.
They are more-or-less alike Arduino boards in terms of board size and on-board resources except they
don’t share same pin naming conventions and board layouts. Well that’s not a big issue. However, it
would have been better if the Launchpads shared Arduino-like form factor. This would have enabled
using Arduino shields with Launchpads. TI has, however, its own brand of shields called BoosterPacks
and they seem to like promoting their own idea, owing to which there’s still no official TI Launchpad
that share exactly Arduino form-factor/shape. It is a very aggressive marketing boldness. Shown below
is the BOOSTXL-EDUMKII BoosterPack. It is just like Arduino Esplora with lots of on-board sensors and
devices except for the MCU. It is good for game development and sensor applications. There are other
useful BoosterPacks dedicated for capacitive touch, displays and so on.
Launchpad boards are not the only development boards offered by TI. There are many other dev
boards too. Shown below is the TI MSP-EXP430F5438 Bluetooth platform development board.

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However due to cheapness and relatively good availability Launchpad boards are by far most popular,
particularly the MSP-EXP430G2 Experimenter’s Launchpad board.
This board comes boxed with two micros –MSP430G2452 and MSP430G2553. Both of these mixed-
signal MCUs come in PDIP packages. We can take them off from the board and use them in bread
boards, strip boards, PCBs, etc. Shown below is the layout of a MSP-EXP430G2 Launchpad board.

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Just like any other evaluation kit, every Launchpad comes embedded with user LEDs, buttons, I/O port
headers (also known as BoosterPack connectors), onboard power supply, USB-to-serial converter and
programming interfaces.
MSP430s are ultra-low power 16-bit general purpose microcontrollers. A MSP430 micro consists of a
16-bit RISC CPU, wide variety of feature-rich peripherals and a flexible clock system all under the hood
of a von-Neumann architecture. Because of their ultra-low energy consumption profile, MSP430s are
well-suited for battery/solar powered/limited or renewable energy applications.
MSP430G2452 and MSP430G2553 are both almost identical in terms of hardware peripherals and pin
count. MSP430G2553 has some additional hardware features like more RAM-ROM memories, timers
and USCI-based hardware interfaces for LIN and IrDA communications.

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Shown below is a comparison table of some common MSP430 chips usually found with Launchpad
boards.
Other Launchpad boards contain other chips but fortunately they share the same pin layout and so
they are fully pin compatible. The fourteen pin parts and twenty pin parts share the same pin layout
as shown below:
Though the pin names are labelled properly on the silkscreens of the boards, it is sometimes necessary
to check the schematic for details. Shown below is the basic schematic of a MSP-EXP430G2 Launchpad.

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From the schematic, we can see what has been placed on the board by default. Parts labelled DNP are
not placed on a fresh Launchpad board. These have been left for the users.
If these don’t matter much and you need something simpler, then there are Arduino-like pin maps for
Launchpads. Though they are made for Energia IDE, they are useful for quick overviews.

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Hardware
We will obviously need a MSP430 Launchpad board. For this tutorial, I used MSP-EXP430G2 Launchpad
board with MSP430G2553 and MSP430G2452 microcontrollers.
Apart from the Launchpad board, we will need basic tools like a digital multimeter (DMM), wires or
jumper cables, a power bank and other stuffs typically available in an Arduino starter kit like the
RIASpire one shown below.
An additional external or off board programmer/debugger is not needed since MSP430 Launchpad
boards come with on board Spy-Bi-Wire (SBW) programming/debugging interface. This interface

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utilizes pins labelled TEST and RST apart from power pins and so only four wires are needed. Note
reset pin should be externally pulled up. Check the diagram below.
Similarly, we don’t need to buy/use any external USB-serial converter for serial communication as the
boards come with onboard hardware for this communication.
In all Launchpad boards, there are headers with jumpers as shown below to separate onboard
programmer from the target. This allows us to use a Launchpad board as standalone programmer. We
can also detach it. The top dotted line marks the border between the target and the programmer.

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It is still nice to have one external MSP-FET programmer. FET stands for Flash Emulation Tool and it
supports both JTAG and SWD interfaces. FETs are pretty expensive tools.
Lastly, I strongly recommend having an oscilloscope or a logic analyser for checking signals and timing-
related info. In many cases, informations provided by these tools become extremely necessary.

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Software
There are numerous ways of learning and using a new microcontroller family effectively. A number of
C/C++ compilers are available for coding MSP430 micros. Hobbyists and novice users find Arduino-like
solutions easy and quick but from an engineer’s perspective such solutions are inexplicably incapable
of extracting the sweet fruits of a well-armed microcontroller. Rawer approaches are preferred by
professionals but they too seek reduced efforts and quick solutions. The learning curve is also needed
to be a smooth one. In this segment, we will checkout some common software solutions for MSP430s.
Firstly, there is the free open-source Energia IDE. This is an Arduino-like IDE that enables users to code
MSP430s in the Arduino way. It supports many Launchpad boards including those which are based on
ARM cores. I have used it a lot and it is fun using it for simple hobby projects. However, I wanted to
harness the true power of MSP430s. As with Arduino, you can access MSP430 registers in Energia too
but that doesn’t make significant differences in terms of coding efficiency and memory consumptions.
Energia has the same issues as with Arduino. Arduino framework on top of an AVR makes it much less
robust when compared to a crude AVR. The same thing applies for Energia too. Another key limitation
of Energia is the fact that not all MSP430 chips are supported by it. Energia is, however, very easy to
use, quick and useful for rapid prototyping or testing. The costs are low overall efficiency and larger
code size. Just like Arduino, Energia is not well-suited for highly sophisticate professional projects. It
is just a rapid prototyping tool that we can use to check a proof-of-concept but not the right tool to
build that concept. A smaller hammer is useful for nailing a pin but it is not the perfect tool for breaking
a giant boulder.
Energia is available at http://energia.nu/.
Please note that Energia is not supported by the Arduino LCC which means it not developed or
maintained by the guys from the Arduino team. This doesn’t matter much for its users. However, the
IDE is not frequently updated like the Arduino IDE.

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Next, we have TI’s own compiler – the Code Composer Studio (CCS). CCS is a C/C++ compiler based on
Eclipse IDE. CCS comes with TI’s proprietary compilers that are best in code optimization. Those who
have used Eclipse-based IDEs before know the advantages Eclipse framework brings with it. It has an
excellent code navigation system, perspective views, refactoring, etc. CCS compiler comes with all of
these stuffs and many more like debugger interface and TI App Store. Apart from all these there are
some helpful cloud-based tools from TI. This tutorial is based on CCS compiler. It is free for download
from TI’s website - http://www.ti.com/tool/ccstudio. Make sure you have a TI account.
Then there is IAR compiler. I have never used IAR products but I have heard from many that it is very
popular and widely used. However, it is expensive too.
Lastly, like for many other platforms we have the free open-source GCC compiler for MSP430s.
MSP430 GCC can be integrated with CCS IDE.
We will see during coding that compilers don’t make significant differences in coding style, making
codes cross-platform compatible. I also intend to keep things simple and quick. This is why I focus on
tools rather than other stuffs. With right set of tools, any issue can be addressed decently and rapidly.
Additionally, some more software tools are needed for supportive purposes. Proteus VSM is a good
interactive simulator cum PCB design software. Luckily it supports MSP430 micros. However, it is very
expensive unless you are using a pirated version of it. Frankly speaking, I have never advocated for
simulations because simulations do not address the real-world challenges we encounter in a real-life
real-time project. Simulations, for example, cannot simulate real-world environment conditions nor
can they emulate situations which result in “hang”-like stuck up conditions. Simulations don’t take the
effect of noise and electromagnetic disturbances into account. Additionally, sometimes simulations
give wrong results. I have spent many wasted hours trying to debug an issue with simulation only to
find out that the simulation was incorrect. Still however, simulations are helpful in some special cases.
For instance, when designing a LCD menu, simulation is a time and effort saver. Personally, I
recommend and use real-world debugging over simulations. This gives me a lot of confidence.

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The coolest stuffs for MSP430s are TI’s MSP430Ware driver libraries (driverlib) and GRACE. Driver
libraries remove the pain of traditionally coding MSP430s using registers. Driver libraries provide easy-
to-use API functions for configuring MSP430 peripherals just like the Standard Peripheral Libraries
(SPL) of STM8 micros. However, these libraries are only supported for the newest and resource-rich
MSP430 microcontrollers like the MSP430F5529LP. This idea of driver libraries is quickly gaining mass
popularity and is becoming standard day-by-day for all modern era micros. MSP430Ware can be
downloaded for free from http://www.ti.com/tool/mspware.
You can use TI’s Resource Explorer to check out what’s in driverlib and if your target MCU is supported.
GRACE, on the other hand, is intended for relatively less-resourceful micros like the MSP430G2231
that are mostly well-suited for lower level assembly language environments. GRACE is basically a

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graphical code generator tool, much like the STM32CubeMX that can be used to generate setup
configuration codes for MSP430F2xx, MSP430G2xx and some FR series micros. However, GRACE only
generates register values for small MSP430 micros. For large and advanced MSP430 micros driverlib-
based codes are generated instead of register-level codes. The rest is just like coding any other
microcontroller. Throughout this tutorial, GRACE has been used for all demos.

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As we can see the generated code snippet sets appropriate registers as per our setup in GRACE GUI.
GRACE can be downloaded without any charge from TI’s website:
http://www.ti.com/tool/GRACE?keyMatch=grace%203&tisearch=Search-EN-Products.

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We will also need a separate standalone programmer GUI tool. Why? Because it looks totally stupid
to open the heavy CCS software every time to upload a code to a new target after having built the
final code for it. For this purpose, we will need UniFlash programmer GUI.
UniFlash can be downloaded from http://www.ti.com/tool/uniflash or can be accessed via TI cloud.
Additionally, I recommend installing and using Sublime Text (https://www.sublimetext.com/3) or
Notepad++ (https://notepad-plus-plus.org/download/v7.4.2.html) as a code viewer/editor.
Make sure you also downloaded Launchpad board drivers from here:
http://www.ti.com/lit/sw/slac524/slac524.zip.

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Documents, Pages and Forums
The following documents must be acquired:
•Device Datasheet.
This write up covers MSP430G2452 and MSP430G2553 microcontrollers and so we will be
needing the datasheet of these microcontroller for technical specs and characteristics. These
can be found in the following links:
http://www.ti.com/lit/ds/symlink/msp430g2452.pdf
http://www.ti.com/lit/ds/symlink/msp430g2553.pdf
If you are using some other microcontroller then you must acquire its datasheet first.
•Reference Manual.
MSP430G2xx reference manual covers the details of all the hardware available in this family
of microcontrollers. Unlike other microcontrollers, datasheet of a MSP430 micro, only says
about technical specs and characteristics. Reference manuals say about internal hardware,
how to use them and about internal registers. This is the most important document of all.
http://www.ti.com/lit/ug/slau144j/slau144j.pdf
•Launchpad User Manual and Associated Files.
Visit the following link for Launchpad board user manual and other docs:
http://www.ti.com/tool/msp-exp430g2. This document not just introduces the Launchpad
board, it also contains schematics, layouts and other stuffs. Off all the stuffs in the user
manual, Launchpad board’s schematic is the most valuable thing.
•App Notes.
Though not mandatory, having a collection of MSP430 application notes is a surplus. These
show various ideas and design concepts. Visit TI’s website for these docs.
There are some important websites, online communities and forums that are very helpful. Some of
the most popular ones are:
http://www.43oh.com/
http://forum.43oh.com/
https://e2e.ti.com/support/microcontrollers/msp430/
http://processors.wiki.ti.com/index.php/Main_Page
http://www.ti.com/lsds/ti/microcontrollers-16-bit-32-bit/msp/overview.page
http://www.ti.com/lsds/ti/tools-software/launchpads/overview/overview.page

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Starting a New CCS Project
Beginning a new CCS project is not too complicated. Provided that CCS is installed in your PC, simply
run it.
In just a few seconds, CCS’s logo splashes.
You’ll be asked for workspace location. Either select an existing workspace if you have one or create
a new one.

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Next click File >> New >> CCS Project.
The following window will show up then: