Mitsubishi Electric FX5U Series, Training Manual

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32-bit data instructions and their necessities
• This section describes the concept of two words.
• This section describes the differences between a one-word instruction and two-word instruction.
• The unit of the data memory of the programmable controller is one word that consists of 16 bits. Thus, data is typically
processed in units of one word at the transfer processing, comparison, and arithmetic operation.
• The programmable controller can process data in units of two words (32 bits). In that case, "D" is added at the
beginning of each instruction to indicate that the instruction processes two-word data. The following shows examples.
• The following shows the weights of 32 bits.
As the case of 16-bit data processing, the programmable controller takes the 2's complement in 32-bit data processing.
Thus, the most significant bit b31 (b15 for 16-bit data) is processed as a sign bit.
Instruction
Transfer MOV(P) DMOV(P)
Comparison <, >, <=, >=, =, <> D<, D>, D<=, D>=, D=, D<>
Arithmetic operation +(P) D+(P)
-(P) D-(P)
*(P) D*(P)
/(P) D/(P)
Available range of
numerical values -32768 to 32767 -2147483648 to 2147483647
Available range of digit
specification K1 to K4 K1 to K8
1 word
16 bits
32 bits
2 words
1073741824
-2147483648
536870912 268435456 134217728
67108864 33554432 16777216
8388608 4194304 2097152 1048576
131072
65536 32768 16384
8192 4096 2048 1024
512 256 128
64 32 16
8 4 2 1
262144 524288
b31 b16 b0 b15 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •
b31 b0 • • • • • • • • • • • • • • • • • • • • • • • • • • • •
Most significant bit
0: Positive value
1: Negative value
Available range of values
-2147483648 to 0 to 2147483647
(Sign bit)
• Whether data is processed as two-word (32-bit) data or not depends on the size of the data.
In the following cases, use two-word instructions.
(1) When the data size exceeds the range (-32768 to 32767) in which data can be processed as one word
D100 DMOV K50000
D101 D100
50000
50000
Transferred
Stored in two
adjacent device
areas.
(d) (s)
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