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A.5
Bus States During Instruction Execution
Table A-6 indicates the types of cycles that occur during instruction execution by the CPU. See
table A-4 for the number of states per cycle.
How to Read the Table:
Instruction
1
JMP@aa:24
R:W 2nd
Legend
R:B
Byte-size read
R:W
Word-size read
W:B
Byte-size write
W:W
Word-size write
:M
Transfer of the bus is not performed immediately after this cycle
2nd
Address of 2nd word (3rd and 4th bytes)
3rd
Address of 3rd word (5th and 6th bytes)
4th
Address of 4th word (7th and 8th bytes)
5th
Address of 5th word (9th and 10th bytes)
NEXT
Address of next instruction
EA
Effective address
VEC
Vector address
976
2
3
Internal operation,
R:W EA
1 state
Order of execution
4
5
End of instruction
Read effective address (word-size read)
No read or write
Read 2nd word of current instruction
(word-size read)
6
7
8
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