SBB

 


Opcode

Operand

Description

SBB

R

M

Subtract register or memory from accumulator

with borrow

 

 

—  The contents of the register or memory location and Borrow Flag (i.e. CY)

are subtracted from the contents of the accumulator.

 

—  The result is stored in accumulator.

—  If the operand is memory location, its address is specified by H-L pair.

—  All flags are modified to reflect the result of subtraction.

—  Example: SBB B or SBB M

Comments

Post a Comment

Popular posts from this blog

MOV

  Opcode Operand Description MOV Rd,Rs Rd,M M, Rs Copy from source to destination.   —    This instruction copies the  contents  of the source  register into   the destination register. —    The  contents  of the source  register are  not   altered. —    If one of the operands is a memory location, its location is specified   by the contents of the HL registers. —    Example:  MOV  B,   C —     MOV  B,   M —    MOV M,   C  
Read more

CMP

  Opcode Operand Description CMP R M Compare register or memory with accumulator     —    The   contents   of   the   operand   (register   or   memory)   are  compared  with the  contents  of the   accumulator.   —    Both  contents  are  preserved   . —    The   result   of   the   comparison   is   shown   by   setting   the  flags  of the PSW as   follows:   —    if (A) < (reg/mem): carry  flag  is   set —    if (A) = (reg/mem):  zero  flag  is   set —    if (A) > (reg/mem): carry and  zero  flags  are   reset. —    Example:  CMP B or CMP   M
Read more

JX- JC, JNC, JP, JM, JZ, JNZ, JPE, JPO

  Opcode Operand Description Jx 16-bit address Jump conditionally     —    The  program  sequence is  transferred  to  the   memory location specified  by  the  16 -bit address  given  in the  operand  based on the specified  flag  of the   PSW. —    Example:  JZ 20 3 4   H. Opcode Description Status Flags JC Jump if Carry CY = 1 JNC Jump if No Carry CY = 0 JP Jump if Positive S = 0 JM Jump if Minus S = 1 JZ Jump if Zero Z = 1 JNZ Jump if No Zero Z = 0 JPE Jump if Parity Even P = 1 JPO Jump if Parity Odd P = 0
Read more