SAN3010
PDS038-SA 2531/2-003 Rev. B 21-03-00
This application note describes a sim ple interface for keyboard entry to the SA253x fam ily via a Microcontroller. It
also includes hardware description , flowchart and a software example based on the 80Cxx - family of
Microcontrollers.
•
only 5 outputs and 1 input required from µC for handshake to access all keys in the SA253x keyboard matrix
•
universal interface, not restricted to specific Microcontrollers
•
supports both 3V- and 5V- µCs
•
same hardware for all single chip telephones : SA2531/2
•
same software for all single chip telephones, only key labels must be replaced
Table of Contents
1 SCOPE............................................................................................................................................................................................................. 1
2 KEY FEATURES ..............................................................................................................................................................................................1
3 OTHER APPLICABLE DOCUMENTS AND PAPERS ......................................................................................................................................1
4 REVISION STATUS .........................................................................................................................................................................................2
5 GENERAL DESCRIPTION ...............................................................................................................................................................................2
6 HARDWARE CONFIGURATION ......................................................................................................................................................................2
7 APPLICATION SCHEMATIC:...........................................................................................................................................................................2
8 SCANNING TABLE/FLOWCHART...................................................................................................................................................................3
9 SAMPLE SOFTWARE......................................................................................................................................................................................3
10 KEY ENTRY SIGNAL TABLE: .......................................................................................................................................................................4
11 APPENDIX A: APPLICATION SCHEM ATIC ..................................................................................................................................................5
12 APPENDIX B: FLOWCHART:........................................................................................................................................................................6
13 APPENDIX C: SAM PLE SOFTWARE LISTING.............................................................................................................................................7
14 LIABILITY AND COPYRIGHT STATEMENT................................................................................................................................................13
1. Data Sheet SA2531, SA2532
2. Pin-out Comparison SA2531/2
3. Product Presentation
4. Single Chip Telephone Evolution (Apr. 16, 1996)
sames
samessames
sames
SAN3010
APPLICATION NOTE
SINGLE CHIP TELEPHONE INTERFACE FOR
KEYBOARD ENTRY VIA uC
1 Scope
2 Key Features
3 Other applicable documents and papers
