the m31 is a low voltage electret condenser microphone specifically designed for the measurement of transducers, loudspeaker systems, room response, and other similar acoustic characteristics.
pcie總線的層次組成結構與網絡中的層次結構有類似之處,但是pcie總線的各個層次都是使用硬件邏輯實現的。在pcie體系結構中,數據報文先在設備的核心層(device core)中產生,然后再經過該設備的事務層(transactionlayer)、數據鏈路層(data link layer)和物理層(physical layer),終發送出去。