This schematic shows the Atmel AVR ATmega162 circuit as it was built on the test board. The power supply is common and is shared between all of the microcontrollers on the board. Other than that, each microcontroller is in its own minimal circuit. The ATmega162 is using its internal 8 MHz RC oscillator (divided by 8). The circuit applies to the ATmega8515 as well. The ATmega162 is similar to the ATmega8515, but the ATmega162 does not have the external memory interface, and has twice the memory (16k vs. 8k).
Here you can find the current ATmega162 datasheet