d/a conversion

Hello,
How we can convert the digital o/p from microcontroller to analog using PWM.Whether the o/p of avr will maintain the previous value of analog irrespective of whether the microntroller doing whatever the work.

use simple D/A converter..

and can you please elaborate this..

Whether the o/p of avr will maintain the previous value of analog irrespective of whether the microntroller doing whatever the work.

manuman