ARM Spec Study

最近要開始讀ARMv8 spec，想說對作system來講，重點的東西要看那些
以下是自己歸納的:
1. States: instruction state, execution state, security state
2. Programming mode, register, datatype
3. Memory & protection
4. Interrrupt & exception vector table (ARM defines interrupt as a special type of exception)
5. I/O
6. Coprocessor


突然回憶起上學期Computer Architecture的時候有一堂課教的東西好像就是在講看電腦系統需要注意的點
回去翻了一下教課書"Computer Architecture, A Quantitative Approach"
Chap 1.3 "Defining Computer Architecture"
提到The word architecture covers all  three aspects of computer design—instruction set architecture, organization, and hardware. 
ISA就是軟硬體間的橋樑，也就是軟體的設計者需要知道的東西 (我在想只有像compiler這種系統軟體才需要知道)
其中organization: the high-level aspects of a computer's system，像是CPU pipeline、memory hierachy...


像是processor mode、memory、exception這些mechanism就是屬於organization
所以我想對於做系統來講，要看spec就是要看ISA, organization囉!!!