Page 56 - DCAP210_INTRODUCTION__TO_MICROPROCESSORS

Introduction to Microprocessors

Notes 3.6 Summary

• The microprocessor uses this register to sequence the execution of the instructions.
• An instruction is a binary pattern designed inside a microprocessor to perform a specific
function. The entire group of instructions, called the instruction set
• The ADD, ADI instructions perform addition of register or 8-bit with the contents of the
Accumulator. If the sum is larger than 8-bits, it sets the carry flag
• 8085 microprocessor is a programmable logic chip; it can also perform hardwired logic with
its instruction set. The logical operations performed by includes AND, OR, XOR (Exclusive
OR) and NOT (Complement).
• The jump instructions specify the memory location explicitly. This is a 3-byte instruction.

3.7 Keywords

• Accumulator: An accumulator is a register in which intermediate arithmetic and logic results
are stored.
• HLT: HLT (halt) is an assembly language instruction which halts the CPU until the next external
interrupt is fired.
• Instruction: An instruction is a command to the microprocessor to perform a given task on a
specified data.
• NOP or NOOP (short for No Operation or No Operation Performed) is an assembly language
instruction, sequence of programming language statements, or computer protocol command
that effectively does nothing at all.
• PC: Program counter is a processor register that indicates where the computer is in its
instruction sequence.

1. Give explanation of 8085 Microprocessor Kit.
2. Write a program to multiply 16-bit number with 8-bit number using 8085.

3.8 Self-Assessment Questions

1. The most commonly used flags are:

(a) bit (b) carry
(c) register (d) buffer
2. The accumulator is also identified as
(a) Flag (b) buffer

(c) register (d) none of these
3. What is one of the following instructions that is used to copy data from a source into a
destination?

(a) MOV B, A (b) COPY B, A
(c) Carry B, A (d) all of these

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