Essay/Software 2006.02.27 00:28
[[ blog 이사 과정에서 정확한 posting날짜가 분실됨. 년도와 분기 정도는 맞지 않을까? ]]
((To avoid misunderstanding) I am also application engineer.)
Application engineer tends to ignore HW characteristics. But, without HW, SW is useless. Even application engineer in embedded software, would better to know basic stuffs about low-layer. Here are some examples about considering these low-layer characteristics. These examples are to appeal to application engineer.
* Each assembly code line may spend different number of CPU clocks. So, counting assembly code line is useless to check CPU performance.
* Optimized code for "2 CPU + 1RAM" is totally different from the one for "2 CPU + 2 RAM for each". Besides, DMA, Bus arbiter etc may also affect to code.
* In some cases, using compressed data is faster than uncompressed one. For example, using highly-compressed-RLE data on the platform which has very-fast-CPU but slow NVRAM. In this case, dominate factor of performance is "performance of accessing NVRAM". So, compressed data has advantage on this. Besides, overhead for uncompress is very low in case of RLE.
Point in here is, "In embedded environment, even application engineer needs to know about it's HW platform where software runs on."
|[Dev] XP에서 말하는 code branch 관리에 대한 의문점... (0)||2007.06.15|
|[Essay] Over-engineering에 대해서... (0)||2007.05.14|
|[Dev] Sometimes, code duplication may need to be allowed. (0)||2006.12.14|
|[Dev] Source code editing 환경의 통일... (0)||2006.10.07|
|[Prog] Layering hardware specific part in software. (0)||2006.04.13|
|[Prog] Basic knowledge about HW is required even to the application engineer. (0)||2006.02.27|