MSP430
The MSP430 was introduced in the late 1990s by Texas Instruments, although its ancestry goes back to the 4-bit TSS400. In summary, it is a particularly straightforward 16-bit processor with a von Neumann architecture, designed for low-power applications. Both the address and data buses are 16 bits wide. The registers in the CPU are also all 16 bits wide and can be used interchangeably for either data or addresses. This makes the MSP430 simpler than an 8-bit processor with 16-bit addresses. Such a processor must use its general-purpose registers in pairs for addresses or provide separate, wider registers.
The MSP430 is the simplest microcontroller in TI’s current portfolio. Its more powerful siblings include the TMS470, which is based on the 32/16-bit ARM7, and the C2000, which incorporates a digital signal processor. Several features make the MSP430 suitable for low-power and portable applications:
The MSP430 is the simplest microcontroller in TI’s current portfolio. Its more powerful siblings include the TMS470, which is based on the 32/16-bit ARM7, and the C2000, which incorporates a digital signal processor. Several features make the MSP430 suitable for low-power and portable applications:
- The CPU is small and efficient, with a large number of registers.
- It is extremely easy to put the device into a low-power mode. No special instruction is needed: The mode is controlled by bits in the status register. The MSP430 is awakened by an interrupt and returns automatically to its low-power mode after handling the interrupt.
- There are several low-power modes, depending on how much of the device should remain active and how quickly it should return to full-speed operation.
- There is a wide choice of clocks. Typically, a low-frequency watch crystal runs continuously at 32 KHz and is used to wake the device periodically. The CPU is clocked by an internal, digitally controlled oscillator (DCO), which restarts in less than 1 µs in the latest devices. Therefore the MSP430 can wake from a standby mode rapidly, perform its tasks, and return to a low-power mode.
- A wide range of peripherals are available, many of which can run autonomously without the CPU for most of the time.
- Many portable devices include liquid crystal displays, which the MSP430 can drive directly.
- Some MSP430 devices are classed as application-specific standard products (ASSPs) and contain specialized analog hardware for various types of measurement