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Altera_Forum
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17 years ago

help needed: passing toggle signals cross clock domain

Hi all...I have a process running at clock A (2.667MHz) which will generate a toggle signal X and I need this signal to pass to clock domain B (80MHz) which a FSM is updating its state according to t...
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Altera_Forum
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17 years ago

The best method to synchronize parallel (multibit) data depends on the nature of the data.

The discussed gray encoding is only applicable to counter values that are known to change by one increment up- or downwards. In the general case, a handshake is needed:

After making the data available at domain A, set a DataReady flag. Latch the data at domain B and set a DataAck flag. At Domain A reset the DataReady flag on DataAck. At Domain B reset the DataAck flag on reset of DataReady. Now both sides are ready for a new transfer.