MSP430 Generations
There are six general generations of MSP430 processors. In order of development, they were the '3xx generation, the '1xx generation, the '4xx generation, the '2xx generation, the '5xx generation, and the '6xx generation. The digit after the generation identifies the model (generally higher model numbers are larger and more capable), the third digit identifies the amount of memory on board, and the fourth, if present, identifies a minor model variant. The most common variation is a different on-chip analog-to-digital converter.
The 3xx and 1xx generations were limited to a 16-bit address space. In the later generations this was expanded to include '430X' instructions that allow a 20-bit address space. As happened with the PDP-11, and as one might expect, extending the addressing range beyond the 16 bit word size introduced some peculiarities and inefficiencies for programs larger than 64 kBytes.
In the following list, it helps to think of the typical 200 mA·Hr capacity of a CR2032 lithium coin cell as 200,000 μA·Hr, or 22.8 μA·year. Thus, considering only the CPU draw, such a battery could supply a 0.7 μA current draw for 32 years. (In reality, battery self-discharge would reduce this number.)
The significance of the 'RAM retention' vs the 'real-time clock mode' is that in real time clock mode the CPU can go to sleep with a clock running which will wake it up at a specific future time. In RAM retention mode, some external signal is required to wake it, e.g. I/O pin signal or SPI slave receive interrupt.
Read more about this topic: TI MSP430
Famous quotes containing the word generations:
“Flowers so strictly belong to youth, that we adult men soon come to feel, that their beautiful generations concern not us: we have had our day; now let the children have theirs. The flowers jilt us, and we are old bachelors with our ridiculous tenderness.”
—Ralph Waldo Emerson (1803–1882)