When we believe that many software engineers and hardware engineers talk often hear the smallest systems. This is a new word, only heard of the system, but where's the minimum system?
In fact, this is not a hardware engineer jargon, but facts dictates. Because a separate single chip even if you give it through the power, it does not necessarily work, why? Because it is missing something, missing what? Missing much, if it does not have an internal oscillator, then it may require an external crystal; it may also need a power supply circuit, because most of the MCU operating voltage of 5 volts or basically 3.3 volts, do not ask why, is so provisions, this requires a stable voltage can not be swayed, calling put the microcontroller to burn. In particular, some new to the hardware brothers, sleepwalk took 220 VAC pick up, fix will be any death. Another is to have to download a program circuit it, it also needs a reset circuit, this single-chip and software programs, they sometimes need to restart, so we get hold of the reset circuit.
In addition, it requires capacitors, resistors, inductors, what indicator. These elements do on-chip microcontroller is not very convenient, but also due to external factors affected the actual values are not the same, so do also to facilitate debugging outside the chip.
Thus, the smallest single-chip system is a single chip together with these basic peripherals and accessories, thereby ensuring SCM start, but what can not do the task, in order to achieve our objective, have increased accessories. What specific increase in accessories, to see what we asked for. For example, to make a timer, there is no need to add any accessories too, and if you want to show what the point of the text, it would have to do to add a LCD display, of course, but also add a drive circuit of the LCD. This and buy a computer as basic is the host, if you want to operate, it should be coupled with a keyboard and mouse, if would like to see the contents, you have to buy a monitor, if want to listen to the voices, then You have to spend money to buy a sound card and speakers. Therefore, the host computer can be seen as a minimum the system.
