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SUB r     Subtract without Carry     Rabbit 4000 Instruction
Opcode
Instruction
Clocks
Operation
---- SUB r 4(2,2) A = A - r

7F 97

SUB A

4(2,2)

A = A - A

7F 90

SUB B

4(2,2)

A = A - B

7F 91

SUB C

4(2,2)

A = A - C

7F 92

SUB D

4(2,2)

A = A - D

7F 93

SUB E

4(2,2)

A = A - E

7F 94

SUB H

4(2,2)

A = A - H

7F 95

SUB L

4(2,2)

A = A - L


Flags ALTD IOI/IOE
S
Z
L/V
C
F
R
SP
S
D
·
·
V
·
·
·

Description

Subtracts r (any of the registers A, B, C, D, E, H, or L) from A. The result is stored in A. The Rabbit 4000 assembler views "SUB A,r" and "SUB r" as equivalent instructions.

The opcodes for these instructions are different than the same instructions in the Rabbit 2000, 3000 and 3000A.

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