link to page 1 link to page 1 link to page 4 link to page 5 link to page 6 link to page 7 link to page 8 link to page 8 link to page 9 link to page 9 link to page 12 link to page 13 link to page 14 link to page 15 link to page 16 link to page 16 link to page 17 link to page 18 link to page 18 Table of Contents Introduction..1 Features.. 1 1. Description...4 2. Configuration Summary... 5 3. Ordering Information..6 4. Block Diagram... 7 5. ATmega103 and ATmega64A Compatibility.. 8 5.1. ATmega103 Compatibility Mode...8 6. Pin Configurations... 9 6.1. Pin Descriptions..9 7. Resources..12 8. Data Retention...13 9. About Code Examples... 14 10. Capacitive Touch Sensing... 15 11. Packaging Information... 16 11.1. 64A... 16 11.2. 64M1...17 12. Errata...18 12.1. ATmega64A Rev. D.. 18 Document Outline Introduction Features Table of Contents 1. Description 2. Configuration Summary 3. Ordering Information 4. Block Diagram 5. ATmega103 and ATmega64A Compatibility 5.1. ATmega103 Compatibility Mode 6. Pin Configurations 6.1. Pin Descriptions 6.1.1. VCC 6.1.2. GND 6.1.3. Port A (PA7:PA0) 6.1.4. Port B (PB7:PB0) 6.1.5. Port C (PC7:PC0) 6.1.6. Port D (PD7:PD0) 6.1.7. Port E (PE7:PE0) 6.1.8. Port F (PF7:PF0) 6.1.9. Port G (PG4:PG0) 6.1.10. RESET 6.1.11. XTAL1 6.1.12. XTAL2 6.1.13. AVCC 6.1.14. AREF 6.1.15. PEN 7. Resources 8. Data Retention 9. About Code Examples 10. Capacitive Touch Sensing 11. Packaging Information 11.1. 64A 11.2. 64M1 12. Errata 12.1. ATmega64A Rev. D