| ??? 09/08/09 08:52 Read: times Msg Score: +2 +2 Good Answer/Helpful |
#168798 - Oscilloscope Responding to: ???'s previous message |
Have you looked with an oscilloscope on all data signals, and verified that they all swings over the full voltage range, and with distinct flanks?
Having a data or address bus with one bit held constantly high or low, or fighting with a neighbour bit, is a common error, and something to start with when external hardware doesn't behave. The next step is to verify that all signals have the proper timing. You can calculate the timing from the source, but for good measure, you should also verify that your theories are correct by measuring on the live hardware. |
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