The 8051 Microcontroller and Embedded

Department of Computer Scien

ce and Information Engineering

National Cheng Kung University, TAIWAN

HANEL

KEYBOARD INTERFACING Grounding Rows and Reading Columns(cont’)

Flowchart for Program 12-4

Start

Ground all rowsRead all columnsAll keys

open?yesno^1

1
Read all columnsAll keys

down?yes

no Wait for debounceRead all columns

All keys down?^2

yes

no