The difference is a 90 degree phase shift between clock and data for DDR and 180 degree phase shift for SDR.
i.e. clock edge alligned with data chnges or in the middle between data changes when the data is stble
The difference is a 90 degree phase shift between clock and data for DDR and 180 degree phase shift for SDR.
i.e. clock edge alligned with data chnges or in the middle between data changes when the data is stble