Z80 Assembly 48: Interrupt Prioritization and the Daisy Chain
The Challenge of Multiple Devices In a complex Z80 system, you might have several devices that need to interrupt the CPU (e.g., a timer, a keyboard controller, and a disk controller). If two devices signal an interrupt at the exact same time, the CPU needs a clear way to decide which one to service first. This is called priority resolution. The Daisy Chain Protocol The Z80 uses a hardware architecture called a Daisy Chain to resolve interrupt priority. ...