AN552 Datasheet PDF

M Author: AN552 SUMMARY Built in pull-up resistors and very low current consumption during sleep make it a very good candidate for battery powered remote operations and applications. Appendix A provides an example of the code. Performance: Code Size RAM Used 64 words 0 bytes Implementing Wake-up on Key Stroke Stan D’Souza Microchip Technology Inc. INTRODUCTION Microchip's PIC16CXXX microcontroller family are ideally suited to directly interface to a keypad. The high 4-bits of PORTB (RB7:RB4) have internal pull-ups and can trigger a “change on state” interrupt. This interrupt, if enabled, will wake the microcontroller from SLEEP. In most battery powered applications, a microcontroller is exercised when a key is pressed (e.g., in a remote keyless entry system). The life of the battery can be extended by using PIC16CXXX microcontrollers. This is done by putting the PIC16CXXX microcontroller into SLEEP mode for most of the time and wake-up only when a key is pressed. FIGURE 1: 4 KEY INTERF...