ATmega1284 / ATmega1284P / ATmega644 / ATmega32 connection guide

• Target rail
  • Bench supply positive
  • VCC (10)
  • AVCC (30)
• Ground
  • Bench supply return
  • GND (11)
  • GND (31)
• Reset
  • RESET (9)

Bench checks

• With power off, check for a short across the supply. Power on and measure voltage at every supply pin and at reset.
• Check the clock source configured by CKSEL. If a used part expects an external clock, provide it before attempting serial programming.

AN2519 §§2–3 and DS40002070B · Pin descriptions and clock source

Connect USART0 to a logic-level serial adapter

• Transmit from MCU
  • PD1 (15)
  • Adapter RX
• Receive into MCU
  • PD0 (14)
  • Adapter TX
• Signal return
  • GND (11)
  • GND (31)
  • Adapter GND

Bench checks

• Configure both sides for the same baud rate, frame length, parity and stop bits. Base the MCU baud divider on the actual clock after prescaling.
• Send a known byte such as 0x55 from the MCU and check that it arrives unchanged. If it fails, inspect TX idle voltage and bit period before attaching the adapter TX line.

DS40002070B · USART0 asynchronous operation and pin assignments

Highlighted contacts are used in the required step or selected circuit. Select a contact to inspect it.

Each package lists the documented order codes and variants covered by this map. Select the marked model to see its peripheral assignments and memory. Check the exact order code and datasheet revision before laying out a PCB.

ATmega1284

128 KiB flash · 16 KiB SRAM · 4 KiB EEPROM. Choose the marked order code for voltage, clock, and temperature.

ATmega1284-PU

128 KiB flash · 16 KiB SRAM · 4 KiB EEPROM · 1.8–5.5 V · 20 MHz maximum · -40 to +85 °C

ATmega1284P

128 KiB flash · 16 KiB SRAM · 4 KiB EEPROM. Choose the marked order code for voltage, clock, and temperature.

ATmega1284P-PU

128 KiB flash · 16 KiB SRAM · 4 KiB EEPROM · 1.8–5.5 V · 20 MHz maximum · -40 to +85 °C

ATmega644

64 KiB flash · 4 KiB SRAM · 2 KiB EEPROM. Choose the marked order code for voltage, clock, and temperature.

ATmega644V-10PU

64 KiB flash · 4 KiB SRAM · 2 KiB EEPROM · 1.8–5.5 V · 10 MHz maximum · -40 to +85 °C

ATmega644-20PU

64 KiB flash · 4 KiB SRAM · 2 KiB EEPROM · 2.7–5.5 V · 20 MHz maximum · -40 to +85 °C

ATmega32

32 KiB flash · 2 KiB SRAM · 1 KiB EEPROM. Choose the marked order code for voltage, clock, and temperature.

ATmega32L-8PU

32 KiB flash · 2 KiB SRAM · 1 KiB EEPROM · 2.7–5.5 V · 8 MHz maximum · -40 to +85 °C

ATmega32-16PU

32 KiB flash · 2 KiB SRAM · 1 KiB EEPROM · 4.5–5.5 V · 16 MHz maximum · -40 to +85 °C

• ATmega1284/ATmega1284P data sheet· DS40002070B · Pin configuration, electrical characteristics, ordering table and serial programming.
• ATmega644 data sheet· 2593O · Pin configuration, electrical characteristics, ordering table and serial programming.
• ATmega32 data sheet· 2503Q · Pin configuration, electrical characteristics, ordering table and serial programming.
• ATmega_DFP Device Family Pack· Machine-readable device definition: package contacts, peripheral routes, and memory sizes.
• AVR Microcontroller Hardware Design Considerations· Power supply, reset network, and programmer connection guidance.
• ATmega1284 documentation and errata· Check current manufacturer documentation, ordering status and silicon revision applicability.
• ATmega1284P documentation and errata· Check current manufacturer documentation, ordering status and silicon revision applicability.
• ATmega644 documentation and errata· Check current manufacturer documentation, ordering status and silicon revision applicability.
• ATmega32 documentation and errata· Check current manufacturer documentation, ordering status and silicon revision applicability.
• AVR source register· Source identifiers, applicability, retrieval dates, and SHA-256 digests.