link to page 1 link to page 1 link to page 4 link to page 5 link to page 6 link to page 6 link to page 7 link to page 8 link to page 9 link to page 9 link to page 12 link to page 14 link to page 16 link to page 17 link to page 18 link to page 19 link to page 19 link to page 20 link to page 20 link to page 21 link to page 22 link to page 23 Table of Contents Introduction..1 Feature.. 1 1. Description...4 2. Configuration Summary... 5 3. Ordering Information ...6 3.1. ATmega328 ... 6 3.2. ATmega328P ...7 4. Block Diagram... 8 5. Pin Configurations... 9 5.1. Pin-out.. 9 5.2. Pin Descriptions..12 6. I/O Multiplexing.. 14 7. Resources..16 8. Data Retention...17 9. About Code Examples... 18 10. Capacitive Touch Sensing... 19 10.1. QTouch Library... 19 11. Packaging Information... 20 11.1. 32-pin 32A.. 20 11.2. 32-pin 32M1-A..21 11.3. 28-pin 28M1..22 11.4. 28-pin 28P3.. 23 Document Outline Introduction Feature Table of Contents 1. Description 2. Configuration Summary 3. Ordering Information 3.1. ATmega328 3.2. ATmega328P 4. Block Diagram 5. Pin Configurations 5.1. Pin-out 5.2. Pin Descriptions 5.2.1. VCC 5.2.2. GND 5.2.3. Port B (PB[7:0]) XTAL1/XTAL2/TOSC1/TOSC2 5.2.4. Port C (PC[5:0]) 5.2.5. PC6/RESET 5.2.6. Port D (PD[7:0]) 5.2.7. AVCC 5.2.8. AREF 5.2.9. ADC[7:6] (TQFP and VFQFN Package Only) 6. I/O Multiplexing 7. Resources 8. Data Retention 9. About Code Examples 10. Capacitive Touch Sensing 10.1. QTouch Library 11. Packaging Information 11.1. 32-pin 32A 11.2. 32-pin 32M1-A 11.3. 28-pin 28M1 11.4. 28-pin 28P3