m9k memory block reading in cyclone3

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reading data from ram ,read data is changing only at the end of address in simulation,ie 0 location data is appearing at 1st location

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This is normal as the address and data of the RAM blocks from the MegaWizard are registered by the clock. This means that there is a delay of one clock cycle before you see the result of a specific address during a read cycle.

When you also add registers at the output, the delay will be two clock periods.