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Duraimurugan Arjunan
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∙ 11y ago
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What is HISR and LISR in embedded systems context?
HISR: High Level ISR (Interrupt Service Routine) LISR: Low Level ISR
How long can the INTR signal stay high?
The INTR pulse can remain high until the interrupt flip-flop is set by the EI instruction in the service routine. If it remains high after the execution of the EI instruction, the processor will be interrupted again, as if it were a new interrupt.
Is pseudo code is a) high level language b) assembly language c) machine language?
in RST interrupt , RST STAND FOR
What is difference between interupt and subroutine?
Interrupt is the signal generated by the input/output devices in order to take the attention of the processor. When the processor receives the interrupt signals it checks the priority status and finish the current fetch and execute cycle and (if the priority status is high) allow the input/output device to process their tasks. Then previous fetch and execute cycle is continued. This is called interrupt service routine. The programs are broken down in to small sub programs which are called subroutines. Then the program reusability, readability, maintainability ...etc will be increased.
Why do you need 8085 maskable interrupts if they can be disabled?
if u want to execute high priority interrupt,at that time of low priority running.So, we can mask the low priority interrupt and execute the high priority interrupt.
What is a high rupture capacity fuse?
This is a fuse that has the ability to interrupt a high fault current.
What is type 2 interrupt?
Type-2 interrupt is called NMI (Non-maskable interrupt).May occur when 8086 receives a low to high transition on it's interrupt response.Could be used for handling critical situations like power failure detection.
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What are Interrupts and their types?
In computing, an interrupt is an asynchronous signal indicating the need for attention or a synchronous event in software indicating the need for a change in execution.A hardware interrupt causes the processor to save its state of execution and begin execution of an interrupt handler. Software interrupts are usually implemented as instructions in the instruction set, which cause a context switch to an interrupt handler similar to a hardware interrupt.Interrupts are a commonly used technique for computer multitasking, especially in real-time computing. Such a system is said to be interrupt-driven.An act of interrupting is referred to as an interrupt request (IRQ).Types of Interrupts1. Level-triggeredA level-triggered interrupt is an interrupt for which an unserviced interrupt is indicated by a particular state, high level or low level, of the interrupt request line. A device wishing to signal an interrupt drives the line to its active level, and then holds it at that level until serviced. It ceases asserting the line when the CPU commands it to or otherwise handles the condition that caused it to signal the interrupt.2. Edge-triggeredAn edge-triggered interrupt is an interrupt signalled by a level transition on the interrupt line, either a falling edge (high to low) or a rising edge (low to high). A device wishing to signal an interrupt drives a pulse onto the line and then releases the line to its inactive state. If the pulse is too short to be detected by polled I/O then special hardware may be required to detect the edge.Edge-triggered interrupts do not suffer the problems that level-triggered interrupts have with sharing. Service of a low-priority device can be postponed arbitrarily, and interrupts will continue to be received from the high-priority devices that are being serviced. If there is a device that the CPU does not know how to service, it may cause a spurious interrupt, or even periodic spurious interrupts, but it does not interfere with the interrupt signalling of the other devices. However, it is fairly easy for an edge triggered interrupt to be missed - for example if interrupts have to be masked for a period - and unless there is some type of hardware latch that records the event it is impossible to recover. Such problems caused many "lockups" in early computer hardware because the processor did not know it was expected to do something. More modern hardware often has one or more interrupt status registers that latch the interrupt requests; well written edge-driven interrupt software often checks such registers to ensure events are not missed.3. HybridSome systems use a hybrid of level-triggered and edge-triggered signalling. The hardware not only looks for an edge, but it also verifies that the interrupt signal stays active for a certain period of time. A common use of a hybrid interrupt is for the NMI (non-maskable interrupt) input. Because NMIs generally signal major -- or even catastrophic -- system events, a good implementation of this signal tries to ensure that the interrupt is valid by verifying that it remains active for a period of time. This 2-step approach helps to eliminate false interrupts from affecting the system.4. Message-signaledMain article: Message Signaled InterruptsA message-signalled interrupt does not use a physical interrupt line. Instead, a device signals its request for service by sending a short message over some communications medium, typically a computer bus. The message might be of a type reserved for interrupts, or it might be of some pre-existing type such as a memory write.Message-signalled interrupts behave very much like edge-triggered interrupts, in that the interrupt is a momentary signal rather than a continuous condition. Interrupt-handling software treats the two in much the same manner. Typically, multiple pending message-signalled interrupts with the same message (the same virtual interrupt line) are allowed to merge, just as closely spaced edge-triggered interrupts can merge.5. DoorbellIn a push button analogy applied to computer systems, the term doorbell or doorbell interrupt is often used to describe a mechanism whereby a software system can signal or notify a computer hardware device that there is some work to be done. Typically, the software system will place data in some well known and mutually agreed upon memory location(s), and "ring the doorbell" by writing to a different memory location. This different memory location is often called the doorbell region, and there may even be multiple doorbells serving different purposes in this region. It's this act of writing to the doorbell region of memory that "rings the bell" and notifies the hardware device that the data is ready and waiting. The hardware device would now know that the data is valid and can be acted upon. It would typically write the data to a hard disk drive, or send it over a network, or encrypt it, etc
Does smoking marjiuana stop menstruation?
No. Marijuanna is not known to interrupt the menstrual cycle. Steady, high doses of a narcotic can certainly interrupt the menstrual cycle, though.
Disadvantage of writing OS in high level language such as C?
Nothing. Every modern OS is written in C, except for some little special parts (like interrupt-handling) that are written in Assembly.
What is a non-maskable?
A non-maskable interrupt is an interrupt that cannot be blocked, or masked, by the processor. In the 8085, TRAP is such an interrupt. If TRAP goes high and stays high, an interrupt vector sequence at address 24H will occur, and there is nothing the processor can do to prevent that.However, external hardware can accomplish the same thing. In a project that I designed, I needed a fourth single pin interrupt beyond RST5.5, RST6.5, and RST7.5, but I needed it to be maskable, so I built a flip flop in hardware that I could set or reset which would be AND'ed with the interrupt request to generate a maskable TRAP.
