9.10 8086 Interrupts The 8086 assigns every interrupt a type code so that the 8086 can identify it. Interrupts can be initiated by external devices or internally by software instructions or by exceptional conditions such as attempting to divide by zero. 9.10.1 Predefined Interrupts The first five interrupt types are reserved for specific functions. The […]
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Posts by Farahat
System Desi :n Usin : the 8086 , 8086 Pins and Signals , Clock Generation Signals , Ready Signals , Basic 8086 System Concepts , 8086 Bus Cycle and Address and Data Bus Concepts .
9.9 System Desi :n Usin : the 8086 This section covers the basic concepts associated with interfacing the 8086 with its support chips such as memory and I/O . Topics such as timing diagrams and 8086 pins and signals will also be included. Appendix E provides data sheets for Intel 8086 and support chips. 9.9.1 […]
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Interfacing with Memories , ROMs and EPROMs , Static RAMs (SRAMs) and Dynamic RAMs (DRAMs)
9.9.3 Interfacing with Memories In Figure 9.16, the 16-bit word memory in the 8086 is partitioned into odd and even 8- bit banks on the upper and lower halves of the data bus selected by BHE and A0• This is typically used for RAMs. Note that RAMs are needed when subroutines and interrupts requiring stack […]
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INTEL 8086 Programming examples Part 1
Example 9.1 (a) Determine the effect of each of the following 8086 instructions: i). DIV CH i). CBW iii). MOVSW Assume the following data prior to execution of each of these instructions independently (assume that all numbers are in hexadecimal): (DS) = 2000H, (ES) = 4000H, (CX) = 0300H, (AX)= 0091H, (20300H) = 05H, (20301H) […]
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INTEL 8086 Programming examples Part 2
Example 9.11 Write an 8086 assembly program that converts a temperature (signed) from Fahrenheit degrees stored at an offset contained in SI to Celsius degrees. The program stores the 8-bit integer part of the result at an offset contained in DI. Assume that the temperature can be represented by one byte and, DS is already […]
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Processor Control Instructions , 8086 Assembler-Dependent Instructions , Typical8086 Assembler Pseudo-Instructions or Directives , SEGMENT and ENDS Directives , ASSUME Directive , DUP, LABEL, and Other Directives , 8086 Stack and 8086 Delay routine
9.5.8 Processor Control Instructions Table 9.11 shows the processor control functions. Let us explain some of the instructions in Table 9.11. ESC mem places the contents of the specified memory location on the data bus at the time when the 8086 ready pin is asserted by the addressed memory device. This instruction is used to […]
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Unconditional Transfer Instructions , Conditional Branch Instructions , Iteration Control Instructions and Interrupt Instructions
9.5.1 Unconditional Transfer Instructions Unconditional transfer instructions transfer control to a location either in the current executing memory segment (intrasegment) or in a different code segment (intersegment). Table 9.5 lists the unconditional transfer instructions. The 8086 CALL instructions provide the mechanism to call a subroutine into operation while the RET instruction placed at the end […]
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Intel 8086 : 8086 Instruction Set , Data Transfer Instructions , Arithmetic Instructions , Bit Manipulation Instructions and String Instructions
9.5 8086 Instruction Set The 8086 has approximately 117 different instructions with about 300 op-codes. The 8086 instruction set contains no-operand, single-operand, and two-operand instructions. Except for string instructions that involve array operations, 8086 instructions do not permit memory-to-memory operations. Appendices F and H provide 8086 instruction reference data and the instruction set (alphabetical order), […]
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Questions and problems
QUESTIONS AND PROBLEMS 8.1 What is the basic difference between main memory and secondary memory? 8.2 Compare the basic features of hard disk, floppy disk and Zip disk. 8.3 What are the main differences between CD and DVD memories? 8.4 Name the methods used in main memory array design. What are the advantages and disadvantages […]
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Intel 8086 : 8086 Addressine Modes , Register and Immediate Modes , Memory Addressing Modes , Port Addressing and Relative Addressing Mode
8086 Addressine Modes The 8086 provides various addressing modes to access instruction operands. Operands may be contained in registers, within the instruction op-code, in memory, or in I/0 ports. The 8086 has 12 addressing modes, which can be classified into five groups: 1. Register and immediate modes (two modes) 2. Memory addressing modes (six modes) […]
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