| ??? 02/20/07 15:52 Read: times Msg Score: +1 +1 Good Answer/Helpful |
#133332 - Easy ROM interface Responding to: ???'s previous message |
First note that Vss is positive and Vdd is negative.
Connect Vss to +5 volts, an Vdd to -3.3 volts. Then CMOS levels should work. Because speed is not all that important, add series resistors on the ROM outputs to limit current if for some reason they go below ground. Pay attention to the minimum clock frequency. That implies dynamic logic, and the circuit may fail if not clocked at 100KHz. Good luck. |
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