[Repost] Let me talk about the annoying 51 chip
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[Repost] Let me talk about the annoying 51 chip I have been using the 51 chip for a long time. I was originally very dissatisfied with its power consumption, but because its price is getting cheaper and cheaper, its cost performance is still very good, so I can't get rid of it. 1. Sleep. Generally, the system will not be too busy, so proper sleep can still save some power. In some simple systems, taking more time to sleep is the key to saving power. You can see that other chips do not consume power, only the microcontroller is the key. Sometimes, increasing the main frequency will get more sleep time, which will make the system power consumption smaller. However, it is worth noting that frequent switching between sleep and working states will cause the power supply to fluctuate at the mV level, especially for many linear regulators with an output capacity of less than 100mA. Such fluctuations may affect the AD and some other analog circuits in the system, which is worth noting. 2. Power-off. If the power-off mode is entered, many 51 chips cannot be restarted through interruption. You can add a micro-power microcontroller to provide reset. This microcontroller is only responsible for keyboard scanning and resetting the 51 microcontroller, as well as sending keyboard codes to the 51 chip. I have seen a handheld device before, which consumes very little power, but includes large-capacity storage, display, input, data output, retrieval and other functions. Usually, 89C51 is always in a power-off state, but after keyboard operation, it resets and starts running, and automatically powers off after processing the tasks sent by the keyboard. 3. Complex calculations. Complex calculations (such as exponential calculations, floating-point multiplication and division) will definitely take up more system timing. To reduce the sleep time, you can use a table lookup method. In this way, a large-capacity table replaces the on-site calculation. Wouldn't you be able to sleep more time? 4. If the software tasks are reduced to a certain extent, you can consider running the crystal at 32k. In fact, this saves more power, but it means that the 51 software basically has nothing to do at high speed and does not require serial communication. Otherwise, you should face reality honestly. I think that the 51 chip is not very suitable for battery-powered systems, but from the development cycle, its development environment is very good. After all, it can carry relatively large applications of 8-bit machines, and sometimes it has to be used. I think the AVR microcontroller that is closest to the 51 is more suitable for future applications because its performance-price ratio is still good compared to other microcontrollers, unless the 51 chip can achieve an operating current of less than 2mA, a sleep current of less than 500uA, and a power-off current of less than 10uA under 3MIP in the future. The above are my immature ideas, and I hope to get your guidance.
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