What does -- - ; mean in the 51 MCU machine code?

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What does -- - ; mean in the 51 MCU machine code? [Copy link]

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What does -- - ; mean in the 51 single-chip machine code? As shown in the figure below, what do the three symbols -- at 1, ― at 2, and ; at 3 mean in the machine code?

maychang

E8--EF means from E8 to EF.

86;87 means 86 or 87.

maychang

There are 8 instructions at (1), namely "MOV A R0" to "MOV A R7", corresponding to machine codes E8 to EF.

There are 8 instructions at (2), namely "MOV data R0" to "MOV data R7", corresponding to machine codes 88 to 8F.

There are two instructions at (3), namely "MOV data @R0" and "MOV data @R1", and the corresponding machine codes are 86 and 87.

shuangchafeng

The second floor explains it in great detail!

老人河

If the instruction is: MOV A, R0 then the machine code is: E8 If the instruction is: MOV A, R1 then the machine code is: E9

吾妻思萌

01234567 is 89ABCDEF, one to one correspondence

suncat

-- indicates the range of all values from the minimum to the maximum. For example, E8--EF means the eight values E8; E9; EA; EB; EC; ED; EE; EF

For MOV A, @Rn, this instruction is applicable to the eight registers R0, R1, R2, R3, R4, R5, R6, and R7.

MOV A, @R0

MOV A, @R1

MOV A, @R2

MOV A, @R3

MOV A, @R4

MOV A, @R5

MOV A, @R6

MOV A, @R7

The range is 8, and the corresponding machine codes are E8, E9, EA, EB, EC, ED, EE, EF

; indicates an independent value: such as 86; 87

For MOV #data, @Ri, there are actually only two instructions corresponding to it:

MOV #data, @R0

MOV #data, @R1

So there are only two ranges, and the corresponding machine codes are 86 and 87

starcat123

The above big guys said the correct answer, the correct answer

8~15 (F)

n: 0~7

i: 0,1

I recently downloaded ATMEL's assembler documentation, called "C51ASM User Guide". I find it very useful, authoritative, and original (the original words of the instruction abbreviations are all complete)