Loop instruction in 8086

Branch Instructions iv. Loop Instructions v. Machine Control Instructions vi. Flag Manipulation Instructions vii. Strings and String Handling Instructions : The 8086 microprocessor is equipped with special instructions to handle string operations. Complete 8086 instruction set documentation. Contribute to michaelsergio/nasm-instruction-set development by creating an account on GitHub. Movsb Instruction In 8086 Example. This instruction allows a loop counter to be updated without disturbing the CF flag. (Use a ADD instruction with an immediate operand of 1 to perform an increment operation that does updates the CF flag.) This instruction can be used with a LOCK prefix to allow The instruction set of the 80286 was almost identical to the 8086 and 8088, except for a few additional instructions that managed the extra 15M bytes of memory. The clock speed of the 80286 was increased, so it executed some instructions in as little as 250 ns (4.0 MIPs) with the original release include 'emu8086.inc' #make_COM# ORG 100h MOV AL, 5 CMP AL, 5 JBE label1 PRINT 'AL не меньше 5' JMP exit label1: PRINT 'AL меньше или равен 5' exit: RET. Logical instructions are the instructions which perform basic logical operations such as AND, OR, etc. In 8086 microprocessor, the destination operand need not be the accumulator. Following is the table showing the list of logical instructions 8086 Instruction Encoding-1. Instruction Format (Cont'd) ! Instruction may also be optionally preceded by one or more. prefix bytes for repeat, segment override, or lock prefixes In 32-bit machines we also have an address size override prefix and an operand size override prefix ! It is primarily used in loop instruction to store loop counter. 4. DX Register: DX register is used to contain I/O port address for I/O instruction. The instruction transfers AL (00500) AH (00501). Data Transfer Between CPU and the Port. Port addresses in 8086 are assigned either 8bit port address or Instructions to transfer the instruction during an execution with some conditions ?. JA/JNBE ? Used to jump if above/not below/equal instruction satisfies. Following is the list of instructions under this group ?. LOOP - helps to loop a group of instructions until and unless the condition satisfies, i.e 8086/8088 Instruction code format with different word lengths: Operation code/addressing mode byte format: In the first byte, W indicates the type of LOOP instruction: It is required to use CX as a counter. The operation of the instruction is to subtract 1 from the content of CX. If the result is not Intel 8086 Instruction Timing. 2. Instruction NOT AND, OR, XOR. Conditional Jump Instruction JMP. Int lea loop loope, loopz loopne, loopnz. Description Intrasegment direct.