nocc_start, nocc_end的含义？

kenaz

各位，
请问AVRdef.h里的这两个指令是做什么的：nocc_start,  nocc_end

我也没找到这两个指令的含义，不知道是做什么的，谢谢！！！

cne53102

nocc = no code compressor，禁止代码压缩器。

《ICCV8 for Cortex – C Cross Compiler for the ARM Cortex-M》page 136.
Sometimes you may wish to disable the code compressor temporarily.
For example,perhaps the code is extremely timing-sensitive and it cannot afford to lose cycles by going through the extra function call and return overhead.
You can do this by bracketing code fragments with an instruction pair:
asm(“.nocc_start”);
...
asm(“.nocc_end”);
The code compressor ignores the instructions between these assembler directives in the fragment.