QUESTIONS AND PROBLEMS 9.1 What is the basic difference between the 8086, 8086-1, 8086-2, and 8086-4? 9.2 Assume (DS)=1000H, (SS)=2000H, (CS)=3000H, (BP)=OOOFH, (BX)=000AH before execution of the following 8086 instructions: (a) MOV CX,[BX] (b) MOV DX,[BP] Which instruction will be executed faster by the 8086, and why ? 9.3 What is the purpose of the […]
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INTEL 8086
Interfacing an 8086-Based Microcomputer to a Hexadecimal Keyboard and Seven-Segment Displays , Basics of Keyboard and Display Interface to a Microcomputer and Hex Keyboard Interface to an 8086-Based Microcomputer
9.12 Interfacing an 8086-Based Microcomputer to a Hexadecimal Keyboard and Seven-Segment Displays This section describes the characteristics of the 8086-based microcomputer used with a hexadecimal keyboard and a seven-segment display. 9.12.1 Basics of Keyboard and Display Interface to a Microcomputer A common method of entering programs into a microcomputer is via a keyboard. A popular […]
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8086 I/O Ports , Important Points To Be Considered for 8086 Interface to Memory and I/O and 8086-Based Microcomputer
9.9.3 8086 I/O Ports Devices with 8-bit I/O ports can be connected to either the upper or the lower half of the data bus. If the I/O port chip is connected to the lower half of the 8086 data lines (AD0- AD7), the port addresses will be even (A0 = 0). On the other hand, […]
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8086 Interrupts , Predefined Interrupts , Internal Interrupts , External Maskable Interrupts , Interrupt Procedures , Interrupt Priorities , Interrupt Pointer Table and 8086 DMA
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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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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