simulation和emulation这两个词的各指什么意思，之间有什么区别？

这四个词描述了accelerator的4个不同的用户模式：

simulation : Just as you use nc-sim, all code runs on a workstation, the hardware accelerator is not used.
acceleration: part of the code(DUT) runs at HW accelerator, part of the code(TB) still runs on workstation.
emulation: all code runs on HW acceleration
in-circuit emulation: not only all code runs at HW accelerator.

simulation:模拟,仿真
emulation:效法,竞争
区别？意思就不一样啊！