Interrupts in 8086 8086 Microprocessor by Ravinder Nath Rajotiya - April 19, 20210 INTERRUPT Services: On the systems running on DOS based platform, certain i/o services are provided by hardware and the operating system. These services are called ROM-BIOS services and DOS services and are the form of interrupts. Need for Interrupt: Interrupts are particularly useful when interfacing I/O devices, that provide or require data at relatively low data transfer rate. Types of Interrupts: There are two types of Interrupts in 8086. They are: (i)Hardware Interrupts and (ii)Software Interrupts (i) Hardware Interrupts (External Interrupts). 8086 microprocessors support hardware interrupts through: Two pins (17 and 18) that Allow interrupt requests, NMI and INTR One pin that acknowledges, INTA, the interrupt requested on INTR. INTR and NMI INTR;is a maskable hardware interrupt. The interrupt can be enabled/Diabled using STI/CLI instructions or using more complicated method
Interrupt Structure of 8085 Microprocessor 8085 Microprocessor by Ravinder Nath Rajotiya - August 28, 2020February 28, 20220 Interrupt structure of 8085 microprocessor: 8085 IC has six pins from PIN 6 to PIN 11, reserved for interrupts these are : TRAP, RST 7.5, RST 6.5, RST 5.5 and INTR. PIN 11 is the interrupt acknowledgement (INTA’) that is generated by the 8085 processor in response to the different interrupts that arrive at the interrupt pin. Figure shows the interrupt structure of 8085 microprocessor. Interrupt priority is shown by the decimal numbers on the extreme left of the figure. As can be see that TRAP has the higher priority marked by digit 1 and INTR has the least priority marked by digit 5 on the left of figure. IVT (Interrupt vector table): IVT contains the interrupt service routine addresses Table-1 (IVT interrupt[t vector
Interrupts in 8085 and interrupt cycle 8085 Microprocessor by Ravinder Nath Rajotiya - August 28, 2020February 28, 20220 We can define interrupt as a process or techniques using which an external slow speed device seek the attention of the microprocessor to informs that it is ready for communication with it. In this post we learn about the interrupt, interrupt cycle and the types of interrupts for 8085 microprocessor