The goal of this application note is to present an example of the use of the HALT mode. In this application, the MCU (here a ST72F264) is waked up by an external interrupt caused by someone pressed a key on the 4x4 matrixed keypad.
This document presents an example application for the ST72F264 microcontroller, demonstrating how to use the HALT mode to achieve low power consumption. The system wakes up from HALT mode via an external interrupt triggered by a key press on a 4x4 matrix keypad.
The document presents an example of using HALT mode to wake up a microcontroller via an external interrupt caused by pressing a key on a keypad.
A user must press the chosen key at least 0.5 to 1 second depending on which specific key is selected.
The microcontroller waits for 4096 CPU clock cycles before running the external interrupt subroutine.