Syntax: SUI 8-bit Where 8-bit is an immediate data operand. Byte: 2byte Addressing Mode: Immediate Addressing Working: 1. 2. 3. 4. Flag Example: SUI 11H where [A]= 22H After execution of SUI 11H [A] = 11H Program: write an ALP for 8bit subtraction of value present in Register A that is 44H with an immediate value 30H. Store result at memory location 5000H. Label Mnemonics Comments Start: SUI 30H STA 5000H Stop: HLT Output: [5000H]= 14H
Instructions of 8085 can be classified on three basis: First Classification on basis of their byte length i.e. size of instruction. 1. 1-byte instructions 2. 2-byte instructions 3. 3-byte instructions Second Classification on basis of their addressing modes i.e. kinds of approaches to fetch and execute. 1. Register Addressing 2. Immediate Addressing 3. Direct Addressing 4. Register Indirect Addressing 5. Implicit Addressing There are five sets of instructions for 8085mp Programming: 1. Data Transfer group 2. Arithmetic group 3. Logical group 4. Branching group 5. Machine Control group
Syntax: XRI 8-bit Where 8- bit is an immediate operand data. Byte: 2byte Addressing Mode: Immediate Addressing Working: 1.This is 2 byte instruction. 2. Microprocessor will allocate first byte for opcode and second byte for immediate data. 3. During execution of this instruction, microprocessor will perform Logical XORing operation between content of Accumulator and Immediate data. 4. S, Z and P are modified . Cy and Ac are reset . Example: XRI 22H where [A]= 11H After execution of XRI 22H [A] = 33H A= 11 = 0001 0001 = 22 = 0010 0010 A=33= 0011 0011 FLAG= 00 0 0 0 1 0 0 = 04H
Comments
Post a Comment