74HC595

代码说明：

  将每2片74595做级联，然后再将级联之后的所有时钟线与数据再并联在一起最后对每一组的锁存控制线做单独控制.(Application to do a project, the more I/O, applied to the 74,595 to do the extension, but you want to mount multi-chip 74595, is bound to have a lot to use the I/O port, in order to solve this problem, I will be every 2 sheet 74595 do cascade, and then cascade after all the clock line and the data in parallel and then together (i.e., all 74595 communal clock and data lines, it only occupies two I/O port lines) Finally, for each group latch control lines do individually controlled (equivalent to Chip Select), so that a hardware circuit by a great degree of simplification, both procedures can also share a driving subroutine 74595, to control the type of lock inventory control line, serial data is sent to the port 74595 cascade module. As a result of the hardware and software have a large degree of optimization.)