3.1.3 Multi-Voltage I/O

The AVR128DB48 MCU has support for Multi-Voltage I/O (MVIO). Port C is reserved for MVIO and is powered from VDDIO2 at 1.8V. The MVSYSCFG fuse controls the AVR128DB48’s supply state. If the fuse is set to single-supply mode, all pins in port C will be tri-stated as the VDDIO2 supply voltage will be below the acceptable range for operation. The default setting for the MVSYSCFG fuse is the dual-supply mode.
Info: 1.8V is selected for VDDIO2 to satisfy the Sequans GM02S module’s requirement of 1.8V I/O without the need for external level shifters.
Table 3-3. MVIO pins
AVR128DB48 PinFunctionConnected Peripheral
PC0USART1 TXGM02S
PC1USART1 RXGM02S
PC2I2C0 SDAATECC608B, VEML3328
PC3I2C0 SCLATECC608B, VEML3328
PC4CTS0GM02S
PC5RESETENGM02S
PC6RING0GM02S
PC7RTS0GM02S