Quote:
Originally Posted by Slothie
The annotations on the buses are correct, so the memory will connect to the unbuffered address bus, but your right in that the diagram is misleading. I will have to redraw the blue line connecting the memory to rest of the circuit to make this clearer. perhaps changing the labels from UAx to BAx would be more appropriate too.
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OK I see that now, I never did like showing a bus connection in a schematic with more than one type of signal in the bus. I saw you had a separate bus for data and just assumed you were following the same standard.
Quote:
Originally Posted by Slothie
I have tried using diodes to route power to chips but not this one specificaly. However the M5M5117 operates down to 4.5v so the ~0.2v schottky diode drop should not cause problems. If it does, I'll just remove the battery function and jumper the diodes.
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One thing to watch out for is that the chip enable will be held low when 5v supply is off. Some ram chips will lock out the chip enable when their supply is below a threshold. I’m not sure if the M5M5117 does that. If it doesn’t then the chip is enabled on battery supply and can run the battery down a bit quicker than it should.