短语词组短语real -time clock word [计]实时时钟字RTC -BATT Real-Time-Clock Battery 实时时钟电池Real -Time-Clock Selection and Optimization 实时时钟的选择与优化RTCCE Real -Time-Clock Chip Elect 实时时钟片选信号Set Real -time Clock 时钟指令 返回 real time clock