One thing we talk a lot about is power budgets, getting as much performance out of a chip, with the least power draw possible. There is of course other budgets, such as space, or one we all know, cost.
When you buy a new Intel Core i7 processor you expect to spend $300 or so. Its common the CPU’s in phones etc cost $10-$20 each. However many applications don’t need or cannot afford that much power. In fact, most CPUs are NOT vastly powerful, or expensive. For example ST just annoucned a ARM Cortex-M3 based 32bit CPU, running at 24MHz, its cost? $0.85. TI has a whole line of its popular MSP430 16bit microcontrollers, running at up to 25MHz, they cost $0.25, yup less then a pack of gum for a fully featured processor.