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ADD instruction
Coding:
(MOD - modifier: affects on operands type - word/byte, or maybe
specifies "short constant"; OP1 and OP2 - operands)
Description:
OP2 + OP1 ==> OP2
This instruction adds OP1 to OP2 and writes the sum to OP2. Flags N and Z are set according
to the result.
Examples:
0212 |
R2 + R1 ==> R2 |
the sum of values from R2 and R1 will be stored to R2 |
0205 |
R0 + (R1) ==> R0 |
the value from R0 adds to the memory cell, which address is taken
from R1 |
02D3
0100 |
R3 + 100 ==> R3 |
add the constant 100 from the second word of this instruction to R3 |
2210 |
R0 + 1 ==> R0 |
increment R0 (add the "short constant" 1) |
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SUBTRACT instruction
Coding:
(MOD - modifier: affects on operands type - word/byte, or maybe
specifies "short constant"; OP1 and OP2 - operands)
Description:
OP2 - OP1 ==> OP2
This instruction subtracts OP1 from OP2 and writes the result to the place
of OP2. Flags N and Z are set accoring to the result.
Examples:
0312 |
R2 - R1 ==> R2
| a difference between values from R2 and R1 will be stored to R2 |
0305 |
(R1) - R0 ==> (R1) |
subtract R0 register's value from the number, extracted from
address (R1); the result will be placed back to the same memory address |
03D3
0100 |
R3 -100 ==> R3 |
subtract the constant 100 (the second word of the instruction) from R3 |
2310 |
R0 - 1 ==> R0 |
decrement R0 (subtract the "short constant" 1) |
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COMPARE instruction
Coding:
(MOD - modifier: affects on operands type - word/byte, or maybe
specifies "short constant"; OP1 and OP2 - operands)
Description:
OP2 - OP1, set flags
This instruction subtracts OP1 from OP2 and sets flags N and Z
according to the result. Both operands don't change - the only
output of the operation are flags.
Examples:
0412 |
R2 - R1 |
set flags according to the difference |
04D3
FFFF |
R3 - FFFF |
compare R3 with the constant FFFF (the second word
of instruction) |
2401 |
R1 - 0 |
analyse the value in R1 (compare with "short constant" 0) |
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MULTIPLY instruction
Coding:
(MOD - modifier: affects on operands type - word/byte, or maybe
specifies "short constant"; OP1 and OP2 - operands)
Description:
OP2 * OP1 ==> OP2
This instruction multiplies OP2 and OP1, and then writes the result
into OP2. Flags N and Z are set accoring to the product.
Examples:
0512 |
R2 * R1 ==> R2 |
values from R2 and R1 will be multiplied |
3510 |
R0 * (-1) ==> R0 |
this example shows, how to change the sign
of R0 value, using "short constant" -1 |
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DIVIDE instuction
Coding:
(MOD - modifier: affects on operands type - word/byte, or maybe
specifies "short constant"; OP1 and OP2 - operands)
Description:
OP2/OP1 ==> OP2
This instruction divides OP2 by OP1, takes an integer part of the result,
and then writes it into OP2. Flags N and Z are set accoring to the
result.
Examples:
0612 |
R2 / R1 ==> R2 |
R2 divided R1 will be stored to R2 |
06D1
0140 |
R0 / 140 ==> R0 |
instruction will divide R1 value by 140
(this word of instruction) and stoped the result to R1 |
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