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in the case of edge trigger, it may generate unwanted interrupt when input signal has glitch and so on.

on the other hand if edge trigger not seen in some special situation (eg. when process in the service routin) level trigger preffered!

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Types of external interrupts?

INTR, RST5.5, RST6.5, RST7.5, and TRAP are external interrupts in the 8085. INTR is the original style used in the 8080. It uses an INTA response and the external hardware is expected to provide an instruction to execute, typically a CALL or an RST. RST5.5, RST6.5, and RST7.5 are non-INTA interrupts, where there is no expected response for acknowledgement. RST5.5 and RST6.5 are level triggered, and RST7.5 is edge triggered. TRAP is similar to the RST interrupts in that there is no acknowledge sequence. It is both edge and level triggered. Further, it is non-maskable.


Is flip flop level triggered or edge triggered?

Flip flop is edge triggered device


Is shift register edge triggered or level triggered?

If the shift register is synchronized (uses clock) the control signal is level triggered. If the shift register is asycronized (no clock) the control signal is edge triggered.


1 What is the difference between a level triggered clock and an edge triggered clock?

in level trigger mode, the input signal is sampled when the clock signal is either high or low whereas in edge trigger mode the input signal is sampled at rising or at the falling edge. lever triggering is sensitive to glitches whereas edge trigger is non sensitive.. example: latch for level trigger and flip-flop for edge trigger


What is maskable in Intel 8085 microprocessore?

Four of the interrupts in the Intel 8085 (INTR, RST5.5, RST6.5, and RST7.5) are maskable, while one interrupt (TRAP) is non-maskable.The eight RSTx type of software "interrupts" are not really interrupts, but if they were treated as interrupts, they would be non-maskable.


Why latch is level triggered?

Because that is the definition of a latch. A J-K flipflop is master-slave triggered because that is the definition of a J-K flipflop. A D flipflop is edge triggered because that is the definition of a D flipflop.


What do you mean by edge triggered flip flop and pulse triggered flip flop?

An edge-triggered flip-flop changes states either at the positive edge (rising edge) or at the negative edge (falling edge) of the clock pulse on the control input.


Level triggered and edge triggered advantages and disadvantages?

Level Trigger:1) The input signal is sampled when the clock signal is either HIGH or LOW.2) It is sensitive to Glitches.Example: Latch.Edge Trigger:1) The input signal is sampled at the RISING EDGE or FALLING EDGE of the clock signal.2) It is not-sensitive to Glitches.Example: Flipflop.


Describe RST 5.5 interrupts in 8085 microprocessor with examples?

RST 5.5 is level triggered interrupt & maskable also. it can be masked by using SIM intrruction. Vector address of the RST 5.5 interrupt is 002Ch


Define Edge Triggered Flip-Flop?

Manner in which a flip-flopis activated by a signal transition.It may be either +ve or -ve edge triggered fliop-flop.


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


What is the differrence of flip-flop and latch?

a group of flip-flops sensitive to pulse duration is called latch whereas a group of flip-flops sensitive to pulse transition is called a register.