ESE 380 Lecture Notes - Lecture 13: Interrupt Vector Table, Universal Asynchronous Receiver-Transmitter, Interrupt Handler

• School: Stony Brook University
• Department: Electrical Engineering
• Course: ESE 380
• Professor: Kenneth Short

Document Summary

I/o peripherals may require the mcu"s attention (service) at any time. The time of occurrence of a service request cannot be anticipated (by the code) An i/o peripheral can signal its need for service by setting an event flag (flip-flop) The flip-flop used as a flag is often called a service request flip-flop. An event is an occurrence of importance to the mcu. An event is often, but not exclusively, associated with the availability of a new data value. Completion of the receipt of serial data by a uart. An event may be represented by the occurrence of a signal transition or a pulse. An event needs to be recorded (stored) until the mcu can respond. A flip-flop is used to record the event. A flip-flop used in this manner is referred to as a service request flip-flop. An event clocks the service request ff, setting it. The mcu must read the service request ff.