Instruction Execution Sequence Step 1 Sn1S n2 01

1
Instruction Execution Sequence Step 1
S(n-1)S (n-2) 01

• Assume
• Op Code has been decoded. This implies that the
  Control Unit can ascertain the Op Code Class as
  well as the Instruction Length (if necessary).
• Addressing Modes has also been decoded.

2
Instruction Execution Sequence Step 2
S(n-1)S (n-2) 01

• Classify Op Code in one of the following
  categories
• a) Data Movement Group. Group Code 00
• b) Data Processing Group. Group Code 01
  
• c) Control Flow Group. Group Code 10
• d) Status Setting Group. Group Code 11
• e) Privileged Group. Mode (M) Changed to
  1
• Execute the Op Code after going to the relevant
  Class.