when deal with the D instruction, shall I determine if it's a jump first?

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when deal with the D instruction, shall I determine if it's a jump first?

woodylcy
I think I must deal with the computing function and jumping function differently at first?

 Do I understand it correctly? thanks for your help.
 
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Re: when deal with the D instruction, shall I determine if it's a jump first?

cadet1620
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All of this happens as combinational logic:
  • The ALU computes its value and sets its condition flags.
  • Those condition flags combine with the jump condition control signals from the instruction decoder to create a jump control signal.
  • The jump control signal changes the inc and load inputs to the PC to change what happens when the system clock fires at the end of the instruction cycle.
--Mark