The timing diagram is a graphical representation of the process in steps with respect to time. It represents the step by step working of each instruction and its execution. The execution time of instructions is represented in T-states. Machine Cycle– The time required to access the memory or input/output device is called the machine cycle. …
The way in which the operand of an instruction is specified is referred to as addressing modes. The addressing mode specifies how the address field of the instruction is to be interpreted before the operand is actually executed. The 8085 microprocessor has 5 types of addressing modes. Immediate Addressing Mode In immediate addressing mode, the …
These instructions affect the operation of the microprocessor. Halt and No operation are the two program control or machine control instructions. Opcode Description HLT Halt1-byte instruction.The processor stops executing and enters waiting state.The address bus and databus are placed in high impedance state. Register contents are not affected. NOP No Operation1-byte instruction.No operation is performed.Generally …
Branch instructions allow the microprocessor to change the sequence of the program, either unconditionally or under certain conditions. Branch instructions are classified into the following three categories. Jump instructions. Call and return instructions. Restart instructions. Jump instructions are classified into two categories: Unconditional and conditional jump instructions. Unconditional Jump Instructions Unconditional jump instructions allow the …
A microprocessor can perform all the logic functions of the hard-wired logic through its instruction set. These instructions include: AND OR Exclusive-OR Compare Rotate Bits All logic operations are performed in relation to the contents of the accumulator. The complete list of logical instructions in 8085 is described in the following table. Mnemonic Description Example …
