2.8 Bus Cycles During Instruction Execution
Table 2-8 indicates the bus cycles during instruction execution by the H8/300H CPU. For the
number of states per bus cycle, see table 2-7, Number of States per Cycle.
How to read the table:
Legend
R:B
Byte-size read
R:W
Word-size read
W:B
Byte-size write
W:W
Word-size write
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
Internal operation
(2 states)
Order of bus cycles
End of instruction
Read effective address (word-size read)
No read or write
Instruction
1
2
3
4
5
6
7
8
JMP @aa:24
R:W 2nd
R:W EA
Read 2nd word of current instruction
(word-size read)
226