c++ - Use of memory in c++

Question

I'm not sure how to pose this question, but here it goes:

1. When programming on my Atmel MCU's in c++ I tend to mix the 'program'-variables and the 'user'-variables in the same datamemory. Which in time is a hassle because I want to make a few presets that can be loaded or saved. And I do not want the 'program'-variables saved because the program will generate the correct values based on the 'user'-values. Is it common practice to split that in memoryplaces? Eg. timercounter in PGM-Memory, thresholdByUser in DATA-memory?

2. In my program i've made several different functions which all have their own set of uservariables. Eg: settings has 5 uservariables, generator has 6 uservariables etc... Would you make 1 big array and then make #define settingsgeneratorSpeed 1, #define settingsBacklight 2 as places, so you could call them as such: Array[generatorSpeed], Array[settingsBacklight] or would you still split it up and collect them by using a struct orso?

Working on atmelstudio 4.0 with a ATMEGA644 on STK500.

Thanks for all the help you can give!

Answer 1

假设您使用的是 AT(X)Mega，当提到 Atmel MCU 时：IIRC 这取决于您使用的编译器套件。使用 gcc，如果您有类似静态 int 的东西，它将转到 PGM 并在程序运行时复制到 RAM。因此，如果您希望变量不在 PGM 内存中，则必须将它们设置为堆栈或堆变量。常量和静态将始终存在于两者中。如果您不想只拥有 PGM 常量，您可以指定它，但这需要特殊的读取操作。

Answer 2

对于问题 2，我会使用const int& settingX = array[Xoffset]而不是定义。但这假设有一些需要遍历数组，否则我只需定义单独的变量。