At91sam7s arm thumb based microcontrollers atmel at91sam7s64c au 32 bit arm thumb based microcontroller at91sam7s family 1 8v to 3 3v supply voltage 64kb flash memory 16kb sram data memory 32 i o pins 8ch x 10bit adc channels 1 timers 4 pwm channels 30mhz clock speed usart spi twi interfaces 64 lqfp case atmel s at91sam7s is a range of general purpose flash microcontrollers that are based on the 32 bit arm risc processor these devices are an ideal migration path for 8 bit users