Fujitsu MB90390 Series, Hardware Manual

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APPENDIX B Instructions
B.5 Execution Cycle Count
The number of cycles required for instruction execution (execution cycle count) is
obtained by adding the number of cycles required for each instruction, "correction
value" determined by the condition, and the number of cycles for instruction fetch.
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Execution Cycle Count
The number of cycles required for instruction execution (execution cycle count) is obtained by adding the
number of cycles required for each instruction, "correction value" determined by the condition, and the
number of cycles for instruction fetch. In the mode of fetching an instruction from memory such as internal
ROM connected to a 16-bit bus, the program fetches the instruction being executed in word increments.
Therefore, intervening in data access increases the execution cycle count.
Similarly, in the mode of fetching an instruction from memory connected to an 8-bit external bus, the
program fetches every byte of an instruction being executed. Therefore, intervening in data access increases
the execution cycle count. In CPU intermittent operation mode, access to a general-purpose register,
internal ROM, internal RAM, internal I/O, or external data bus causes the clock to the CPU to halt for the
cycle count specified by the CG0 and CG1 bits of the low power consumption mode control register.
Therefore, for the cycle count required for instruction execution in CPU intermittent operation mode, add
the "access count x cycle count for the halt" as a correction value to the normal execution count.