Sequential (117) Parallel in/out line

https://chihaukam.blogspot.com/2024/04/blog-post_25.html

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Ref, https://kamchihau.blogspot.com/2026/03/sequential-116.html?m=1

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John : Take a look.  https://chihaukam.blogspot.com/2026/01/john-have-look_8.html?m=1 . It mention about "Circuit". 

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Me: Ok. 

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John : You may take a look at the Picture above.  

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Me: Ok.

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John: When System Circuit put Register_A on RJ45 Circuit, System Circuit can't put Register_A back on System Circuit. 

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Me: Why? 

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John: Because,  the control of Register_A is given to RJ45 Circuit.  System Circuit lose the control of Register_A. <-- Register_A been adopted by RJ45 Circuit. Take a look. 

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1) System Circuit : Set Register_A,  RJ45 Circuit.

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2) System Circuit : Set,  Register_A,  System Circuit.  <--- It's wrong.  After the control of Register_A is given to RJ45 Circuit by System Circuit,  System Circuit lose the control of Register_A. 

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2) RJ45 Circuit : Set, Register_A,  System Circuit.  <--- At that moment,  RJ45 Circuit is the only one who can set Register_A back on the System Circuit. 

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John : When RJ45 Circuit set the Register_A back to the System Circuit,  RJ45 Circuit need a parallel input line.

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Me: This parallel input line must be based on RJ45 Circuit.  This parallel input line can't be based on System Circuit.

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John: Correct.  If this parallel input line is based on System Circuit,  RJ45 Circuit can't set the Register_A back to the System Circuit. 

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John : The conclusion is, "Parallel output and input line is a branch of RJ45 Clock line. ". If you hack the RJ45 Clock line,  you hack the parallel output line too.

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