Hi girl's, guy's and guro's


Having almost finished a new design containing a P89C664 or 668 (1K RAM/8K RAM), I could do with a litle help: How to control battery back up for the internal RAM? There is quite some supervisor chips, but they are primarily designed for external mem., controlling the chip enable. They also seems expensive.........

And should I use a battery or a super cap for back up power?

Thanks

Per Guldmann