Priority Interrupt Daisy Chain Mechanism || Lesson 85 || Computer Organization || Learning Monkey ||

Here we will Priority Interrupt Daisy Chain Mechanism. The daisy-chaining method of establishing priority consists of a serial connection of all devices that request an interrupt. The device with the highest priority is placed in the first position, followed by lower-priority devices up to the device with the lowest priority, which is placed last in the chain. The interrupt request line is common to all devices and forms a wired logic connection. If any device has its interrupt signal in the low-level state, the interrupt the line goes to the low-level state and enables the interrupt input in the CPU. When no interrupts are pending, the interrupt line stays in the high-level state and no interrupts are recognized by the CPU. This is equivalent to a negative logic OR operation. The CPU responds to an interrupt request by enabling the interrupt to acknowledge the line. This signal is received by device 1 at its PI (priority in) input. The acknowledge signal passes on to the next device through the PO (priority out) output only if device 1 is not requesting an interrupt. If device 1 has a pending interrupt, it blocks the acknowledge signal from the next device by placing a 0 in the PO output. It then proceeds to insert its own interrupt vector address (VAD) into the data bus for the CPU to use during the interrupt cycle. Link for playlists: https://www.youtube.com/channel/UCl8x4Pn9Mnh_C1fue-Yndig/playlists Link for our website: https://learningmonkey.in Follow us on Facebook @ https://www.facebook.com/learningmonkey Follow us on Instagram @ https://www.instagram.com/learningmonkey1/ Follow us on Twitter @ https://twitter.com/_learningmonkey Mail us @ [email protected]