Timing diagram for IN C0H.
- Fetching the Opcode DBH from the memory 4125H.
- Read the port address C0H from 4126H.
- Read the content of port C0H and send it to the accumulator.
- Let the content of port is 5EH.
Fig - Timing Diagram for Opcode Fetch Machine Cycle
TIMING DIAGRAM OF 8085 INSTRUCTIONS
Timing diagram for STA 526AH.
- STA means Store Accumulator -The contents of the accumulator is stored in the specified address(526A).
- The opcode of the STA instruction is said to be 32H. It is fetched from the memory 41FFH(see fig). - OF machine cycle
- Then the lower order memory address is read(6A). - Memory Read Machine Cycle
- Read the higher order memory address (52).- Memory Read Machine Cycle
- The combination of both the addresses are considered and the content from accumulator is written in 526A. - Memory Write Machine Cycle
- Assume the memory address for the instruction and let the content of accumulator is C7H. So, C7H from accumulator is now stored in 526A.