4. 8086 Microprocessor- Interrupts Processing – 8087 Numeric Data

University:
Mt. San Antonio College
Course:
ELEC 74 | Microprocessor Systems
Academic year:

2024
Views:

186

Pages:

1
Author:

Dipin K.

The 8086 microprocessor - Interrupts processing – 8087 Numeric data processor - data types The 8086 microprocessor is capable of halting its current operations and jumping to a specific address due to hardware or software events known as interrupts. This capability allows the processor to promptly respond to external events, such as keystrokes, mouse movements, and device errors. External devices, such as I/O ports, timers, or DMA controllers, can generate hardware interrupts, while software instructions, such as the INT instruction, can generate software interrupts. The 8086 checks for pending interrupts at the end of each instruction cycle. Upon detecting a pending interrupt, the 8086 sends an interrupt acknowledge signal to the interrupting device, which responds by placing an interrupt vector number on the data bus. Using the interrupt vector number, the 8086 identifies the corresponding Interrupt Service Routine (ISR) in memory and jumps to the ISR to handle the interrupt. Once the ISR finishes its task, the control returns to the interrupted program using the IRET instruction. Interrupts can be prioritized based on their interrupt vector numbers, with lower vector numbers given higher priority. If multiple interrupts are pending, the highest priority interrupt is serviced first. Additionally, interrupts can be masked using a mask register or a special instruction to prevent recognition by the 8086. The 8087 Numeric Data Processor serves as a coprocessor designed to expedite numeric computations for the 8086 microprocessor. It is a specialized chip capable of performing floatingpoint arithmetic operations, trigonometric functions, and other mathematical calculations more efficiently than the 8086 alone. The 8087 supports a variety of data types, including real numbers in IEEE 754 format (singleprecision, double-precision, and extended-precision), integers in 16-bit, 32-bit, and 64-bit formats, and packed BCD for representing decimal numbers. With a diverse instruction set, the 8087 can execute a broad range of numeric operations, including arithmetic operations, trigonometric functions, and transcendental functions. It also includes data transfer instructions for loading, storing, and converting data between different formats. The 8087 communicates with the 8086 through a specialized interface, allowing the 8086 to issue instructions to the 8087 and the 8087 to interrupt the 8086 upon completing a calculation. The 8087 is particularly beneficial for applications that demand intensive numeric computations, such as scientific and engineering computations, financial calculations, and graphics and image processing. In conclusion, interrupt processing and numeric data processing are critical aspects of the 8086 microprocessor. Interrupts enable the 8086 to respond promptly to external events, while the 8087 coprocessor significantly accelerates numeric calculations, making the 8086 a potent and versatile microprocessor suitable for various applications.