If a **32**-bit processor can handle approximately 4 GiB of RAM (i.e. \$2^{32} = 4 294 967 296\$) bytes, why does my Arduino Mega 2560 have 8 KiB of SRAM, if being a **8**-bit processor allows it to handle just 256 bytes (\$2^8\$)? Or am I reading the following page wrong?

<http://www.atmel.com/devices/atmega2560.aspx?tab=parameters>