| Parameters | 
                                                                                                                        
                                                | Mfr | Microchip Technology | 
                                                                                    
                                                | Series | AVR® ATmega | 
                                                                                    
                                                | Package | Tube | 
                                                                                    
                                                | Product Status | Active | 
                                                                                    
                                                | Core Processor | AVR | 
                                                                                    
                                                | Core Size | 8-Bit | 
                                                                                    
                                                | Speed | 20MHz | 
                                                                                    
                                                | Connectivity | I²C, SPI, UART/USART | 
                                                                                    
                                                | Peripherals | Brown-out Detect/Reset, POR, PWM, WDT | 
                                                                                    
                                                | Number of I/O | 32 | 
                                                                                    
                                                | Program Memory Size | 64KB (32K x 16) | 
                                                                                    
                                                | Program Memory Type | FLASH | 
                                                                                    
                                                | EEPROM Size | 2K x 8 | 
                                                                                    
                                                | RAM Size | 4K x 8 | 
                                                                                    
                                                | Voltage - Supply (Vcc/Vdd) | 1.8V ~ 5.5V | 
                                                                                    
                                                | Data Converters | A/D 8x10b | 
                                                                                    
                                                | Oscillator Type | Internal | 
                                                                                    
                                                | Operating Temperature | -40°C ~ 85°C (TA) | 
                                                                                    
                                                | Mounting Type | Through Hole | 
                                                                                    
                                                | Package / Case | 40-DIP (0.600", 15.24mm) | 
                                                                                    
                                                | Supplier Device Package | 40-PDIP | 
                                                                                    
                                                | Base Product Number | ATMEGA644 | 
                                                                                    
                                                | RoHS Status | ROHS3 Compliant | 
                                                                                    
                                                | Moisture Sensitivity Level (MSL) | Not Applicable | 
                                                                                    
                                                | REACH Status | REACH Unaffected | 
                                                                                    
                                                | ECCN | EAR99 | 
                                                                                    
                                                | HTSUS | 8542.31.0001 | 
                                                                                    
                                                | Other Names | ATMEGA644PAPU | 
                                                                                    
                                                | Standard Package | 10 | 
                                                                                                                
                                
                             
                                                AVR AVR® ATmega Microcontroller IC 8-Bit 20MHz 64KB (32K x 16) FLASH 40-PDIP