Summary of ARM development steps

1. Make a minimum system board: If you have never done ARM development, it is recommended that you do not try to be too ambitious at the beginning and make all the applications complete. Because the startup method of ARM is different from that of DSP or MCU, various problems will often occur. Therefore, it is recommended to first build a small system board with only Flash, SRAM or SDRAM, CPU, JTAG, and reset signal, leaving an expansion interface. If the minimum system can run normally, your task is half completed. Fortunately, the peripheral interfaces of ARM are basically standard interfaces. If you have experience in wiring these hardware, this is a very easy thing for you.

2. Write the startup code. According to the hardware address, write a small code that can be started, including the following parts:

Initialize the port, shield the interrupt, copy the program to SRAM; complete the code remapping; configure the interrupt handle and connect it to the C language entry. You may see that the bootloader has a lot of things in some sample programs given to you, but don't be bothered by these complicated programs, because you are not making a development board, your task is to make a small program to make your application run.

3. Carefully study the information of the chip you are using. Although ARM is compatible in terms of core, each chip has its own characteristics, and these issues must be considered when writing programs. Especially for girls, don't be dependent here. You always want to modify other people's sample programs, but the more you modify them, the more messy they become.

4. Read more operating system programs. There are many open source programs for ARM applications. If you want to improve yourself, you should read more programs from others. Linux, uc/os-II, etc. are all very good source codes.

5. If you are working on hardware, each manufacturer basically has a DEMO board schematic for the chip. Digest the schematic first. This way, when you design in the future, you will have a clear idea of ​​how to allocate resources. You must digest the device's DATSHEET well.

6. If you are working on software, it is best to have some understanding of the operating system mechanism. Of course, this is a piece of cake for software engineers. But if you are a hardware engineer, it will be a bit difficult.