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SBB  -  Subtract with Borrow Instruction


The SBB instruction Subtracts the second operand from the first operand and leaves the result in the first. The carry flag is set to indicate if there is a borrow from the previous subtraction.
This command has 3 parts, Instruction, then either a Register or memory address, followed by a Register, an immediate value or a memory address.

Assembly
Sample		 Description   16 bit Machine
  Code
SBB AL, 0x03;  8 bit immediate from AL  1C 03
SBB AX, 0x0303;  16 bit immediate from AX  1D 03 03
SBB CL, 0x03;  8 bit immediate from an 8 bit Register   80 D9 03
SBB CX, 0x03;  8 bit immediate from 16 bit Register   83 D9 03
SBB CX, 0x0303;  16 bit immediate from a Register   81 D9 03 03
SBB CL, AL;  8 bit Register from 8 bit Register  1A C8
SBB CX, AX;  16 bit Register from 16 bit Register  1B C8
SBB [BX], 0x03;  8 bit immediate from memory address   83 1F 03
SBB [BX], 0x0303;  16 bit immediate from memory address   81 1F 03 03
SBB [BX+2], 0x0033;  16 bit Immediate from memory address  81 5F 02 23 00
SBB AX, [BX];  Memory address from 16 bit Register  1B 07
SBB [BX], AX;  16 bit Register from memory address  19 07
SBB AX, [BX+2];  16 bit Register from memory address  1B 47 02
SBB [BX+2], AX;  16 bit Register from memory address  19 47 02