Atmel 328P alternatives/similar chips with at least 2 UART ports

32-bit AVR UC3

C-Series

Benefits

•Floating point unit (FPU)
•FlashVault™ code protection
•Ethernet support
•Dual CAN and LIN interfaces
•USB with OTG
•PWM with dead-time insertion
•16-channel 12-bit ADC with dual sample-and-hold circuit for simultaneous sampling of 2 signals
•4-channel 1.5 Msps 12-bit analog DAC