说明：  no intro
(C51 in the library function intrins.h cycle _crol_ characters characters left _cror_ cycle shifted to right _irol_ the left circle _iror_ integer integer integer cycle shifted to right _lrol_ long cycle of the left circle _lror_ long integer _nop_ air operation shifted to right 8051 NOP instructions _testbit_ tested and cleared 8051 JBC-bit instruction)