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CHAPTER 6 INSTRUCTION SET
6.5.3 Explanation of “Clocks” column
(1) Number of clocks for accessing word data
The number of clocks shown in the PRAM, EMEM, and SFR columns is when the bus width is 16 bits and
when data is located at an even address. If the bus width is 8 bits, or if data is located at an odd address
even though the bus width is 16 bits, add 4 to the number of clocks shown in the table. Note that the width
of the internal RAM is 16 bits. Also, if word data of the internal ROM is located at an odd address, add 4
to the number of clocks.
If word data is saved to or restored from an odd address by a stack manipulation instruction marked “n”,
add 4 to the coefficient of “n”.
(2) Number of clocks for accessing 3-byte data
The number of clocks shown in the PRAM, EMEM, or SFR column is used when the bus width is 16 bits. If
the bus width is 8 bits, and if data is located at an odd address even though the bus width is 16 bits, add 4
to the number of clocks shown in the table. Note that the bus width of the internal RAM is 16 bits.
(3) If two types of numbers of clocks are shown with each delimited by “/” from the other
If two types of numbers of clocks are shown with each delimited by “/” from the other, two types of numbers
of bytes are shown for that instruction with each delimited by “/” from the other. The execution time of this
kind of instruction is the number of clocks shown at the same side as the number of bytes.
(4) When “n” is shown in “Clocks” column
When the MACW, MACSW, and MOVTBLW instructions are used, the number specified by operand byte
substitutes for “n”.
In the case of the SACW, MOVM, XCHM, MOVBK, XCHBK, CMPME, CMPMNE, CMPMC, CMPMNC,
CMPBKE, CMPBKNE, CMPBKC, and CMPBKNC instructions, the value set to the C register on starting
execution of the instruction substitutes for “n”. This number of clocks is the value when the instruction
execution is not stopped by an interrupt or macro service.
When the shift or rotate instruction is used, the number of bits to be shifted or rotated substitutes for “n”.
When the stack manipulation instruction is used, the number of registers to be saved to the stack or restored
from the stack substitutes for “n”.