TI MSP430
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The MSP430 is a microcontroller family from Texas Instruments. Built around a modern 16-bit RISC CPU, the MSP430 is a high performance device designed for ultra low power consumption. Its mixed-signal performance and raw number-crunching power are also quite extraordinary when compared with many of its 8-bit competitors.
The device comes in a variety of configurations featuring the usual peripherals: 10/12/14/16-bit ADCs, PWM, comparators, timers, USART, LCD driver, watchdog, HW multiplier, internal oscillator, etc. Apart from some older EEPROM (MSP430C3xx) and high volume OTP versions, all of the devices are in-system programmable via JTAG or BSL (Boot Strap Loader via RS-232 link).
The MSP430 is a popular choice for low powered measurement devices. The current drawn when the MSP430 in idle mode is only a few microamps (very few microcontrollers can match it in terms of power consumption) and the cost per chip hovers around a few dollars. There are, however, limitations that prevent it from being used in more complex embedded systems. The MSP430 does not have an external memory bus (which would allow it to efficiently access external RAM/ROM chips) and the limited memory size of the MSP430 variants might be too small for applications that require large data tables. The architecture is also different from other popular microcontrollers (such as the Intel 186).
Texas Instruments provides software development tools that can be downloaded for free. The TI-provided toolchain is a Kickstart edition of the IAR C/C++ compiler, which is limited to 4K of C/C++ code in the compiler and debugger (assembly language programs of any size can be developed and debugged with this free toolchain).
The open source community produces a freely available software development toolset (MSPGCC) based on the GNU toolset, although the object code size and speed are not as optimal as the results from a commercial compiler. Also various commercial development toolsets, which include editor, compiler, linker, assembler, debugger and in single cases code wizards, are available. VisSim, a block diagram language, will generate efficient fixed point C-Code directly from the diagram.
The MSP430 has generated excitement with the availability of inexpensive development platforms. At a cost of US$20, TI itself has packaged a USB fob stick programmer, the ez430, containing an MSP430F2013 on a detachable prototyping board, and CD with development tools. This is helpful for schools, hobbyists and garage inventors. It is also welcomed by engineers in large companies prototyping projects with capital budget problems.
In common with other microcontroller vendors, TI has developed a two-wire debugging interface that replaces the larger JTAG interface found on their parts. Unfortunately, this development has created a "flag day" between old and new development tools. The ez430 stick contains a full USB-connected "FET" (Flash Emulation Tool) for this new two-wire protocol, referred to by TI as "Spy Bi-Wire". It is compatible only with the MSP430F2xxx devices.
The advantage of the Spy Bi-Wire protocol is that it uses only two communication lines, one of which is the dedicated _RESET line. The JTAG interface on all MSP430 parts is multiplexed on other GPIOs. This makes it relatively difficult to debug circuits built around the small, low-I/O-budget chips, since your JTAG hardware will fight with whatever else you have connected to those I/O lines. All those problems disappear with the Spy Bi-Wire-capable chips (which feature a normal JTAG interface in case you still have old development tools).
One other interesting thing about the MSP430F2013 and siblings is that it is practically the only MSP430 part that is available in a DIP package. Other variants in this family are only available in various surface-mount packages. It is clear that TI has gone to some trouble to support the ez430 development platform by making the raw chips easily prototypable by hobbyists.
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