Open Education ResourceOER on Microprocessor 8085 Instruction Set

Open Education Resource-OER on Microprocessor 8085 Instruction Set By Dr. S. N. Sampat, Team leader Ms. R. P. Merchant, Member Mr. A. K. Bilakhia, Member RC-1093 , Group-004, Domain-Electrical and Allied branches Team for OER creation IDP in Educational Technology, IIT Bombay Four-Week ISTE STTP on Use of ICT in Education for Online and Blended Learning 1

Links of OER Different links of various resources like Video, Quiz, Evaluation strategy, Contact through e-mail are available on following URL developed by us* https: //www. 8085 instructions. wordpress. com * Frequent updating activity is being carried out on above URL Four-Week ISTE STTP on Use of ICT in Education for Online and Blended Learning 2

Learning Objectives 1. Define Machine language. 2. Define Assembly Language and need of assembler. 3. Define categories of 8085 instructions. 4. Identify Op Code and Operand of instruction. 5. Identify Registers used in 8085 instructions. 6. Identify valid pairs of 8085 registers used in instructions. Four-Week ISTE STTP on Use of ICT in Education for Online and Blended Learning 3

Evaluation Strategy Sr 1 2 3 4 5 Question Type Multiple Choice Question -MCQ True / False Fill in the gaps Brief Subjective Detailed Subjective Mark 1 1 0. 5 to 1 2 to 3 4 to 6 Above questions would be placed on URL shown in slide 2 Four-Week ISTE STTP on Use of ICT in Education for Online and Blended Learning 4

Introduction l A microprocessor/ microcontroller / DSP instructions given by the user’s program. executes l Instructions should be in a language known to the microprocessor l Microprocessor understands the language of 0’s and 1’s only l This language is called Machine Language. Four-Week ISTE STTP on Use of ICT in Education for Online and Blended Learning 5

Assembler l Microprocessor cannot understand a program written in Assembly language l An Assembler is used to convert Assembly language program to machine language Assembly Language Program Assembler Program Machine Language Code Four-Week ISTE STTP on Use of ICT in Education for Online and Blended Learning 6

Instruction l An instruction is a group of binary bits with special meaning and designed as per architecture of microprocessor / microcontroller / DSP to perform a specific function or operation. l 8085 has 246 instructions. Four-Week ISTE STTP on Use of ICT in Education for Online and Blended Learning 7

Instruction consists of op-code and operand. l Op-code is operational code or command by which microprocessor decides which operation should be done. l Operand is either data or an address on which operation is performed. The length of the data or an address is of either 8 or 16 bit. Example: MOV MVI A, B A, 32 H Four-Week ISTE STTP on Use of ICT in Education for Online and Blended Learning 8

8085 Instruction Category According to number of bytes occupied in memory One byte instruction - includes the op-code and operand in the same byte. Two byte instruction - First byte specifies the op-code and second byte specifies operand as either data or an address of 8 -bit Three byte instruction - First byte specifies the op-code and other two bytes specifies operand as either data or an address of 16 -bit Four-Week ISTE STTP on Use of ICT in Education for Online and Blended Learning 9

Register structure and Memory Microprocessor register structure Program memory Address (16 -bit) Data (8 -bit) A (8 -bit) F (8 -bit) Address (16 -bit) B (8 -bit) C (8 -bit) 2000 XX 3000 YY D (8 -bit) E (8 -bit) 2001 XX 3001 YY H (8 -bit) L (8 -bit) 2002 XX 3002 YY XXXX XX 3003 YY FFFD XX 3004 YY FFFE XX 3005 YY FFFF XX 3006 YY PC (16 -bit) 2000 H SP (16 - bit) FFFE Data (8 -bit) Data Memory Four-Week ISTE STTP on Use of ICT in Education for Online and Blended Learning 10

Instruction Format (One Byte) Task type Task Op-code Operand MOV Rd, Rs (Rd)=(Rs) Rs (A)=(A)+(Rs) Data transfer Copy the contents of the source register to destination register Arithmetic Add the content of any register to ADD the content of an accumulator and save the result in accumulator Logical Complement content of the accumulator Rs= Source register Rd= Destination register R may be A, B, C, D, E, H, L CMA (A)=(A)’ Here Rd, Rs or A is an address of particular register and ( ) indicates the data of that register Four-Week ISTE STTP on Use of ICT in Education for Online and Blended Learning 11

Instruction Format (Two Byte) Task type Task Op-code Operand Data transfer Load an 8 -bit data in to destination register MVI Rd, 8 -bit data (Rd)= 8 - bit data Data transfer Content of input port can be copied in to an accumulator IN 8 -bit port address (A)=( #port) Data transfer Content of an accumulator can be copied to an output port OUT 8 -bit port address ( #port) =(A) Arithmetic Add 8 -bit data to an accumulator ADI 8 -bit data (A)=(A)+8 -bit data Rd= Destination register R may be A, B, C, D, E, H, L Here Rd or A is an address of particular register as well as #port is an 8 -bit address of the port and ( ) indicates the data of that register of port Four-Week ISTE STTP on Use of ICT in Education for Online and Blended Learning 12

Instruction Format (Three Byte) Task type Task Op-code Operand Data transfer Load register pair with 16 -bit data LXI Rp, 16 -bit data Date transfer Transfer the program sequence to the 16 -bit memory address JMP 16 -bit data (PC)= 16 -bit data address Date transfer Transfer the program sequence to the 16 -bit memory address to call subroutine CALL 16 -bit data (PC)= 16 -bit data address (SP)=(SP)2 ((SP)-1)=(PCh) ((SP)-2)=(PCl) Rp = Destination register pair Rp may be AF, BC, DE, HL (Rp)= 16 - bit data Here Rp is address of particular register pair as well as ( ) indicates the data of that register pair Four-Week ISTE STTP on Use of ICT in Education for Online and Blended Learning 13

Classification Of Instruction Set It can be classified as l Data Transfer Instructions l Arithmetic Instructions l Logical Instructions l Branching Instructions l Control Instructions Four-Week ISTE STTP on Use of ICT in Education for Online and Blended Learning 14

Thank you all Four-Week ISTE STTP on Use of ICT in Education for Online and Blended Learning 15