SDR stands for single data rate. In this timing scheme, a digital circuit samples or transmits data only on the rising edge of the clock signal. While simpler to design and route on a circuit board, it offers exactly half the theoretical bandwidth of a dual data rate interface running at the same frequency.
We can stick with standard SDR memory for this controller since the bandwidth requirements are so low.
Do not mix it up with
- DDR: SDR transfers data on one clock edge, while DDR transfers data on both the rising and falling edges.
Related terms
DDR
Double data rate is a clocking technique that transfers data on both the rising and falling edges of a clock signal.
Clock
A continuous square wave signal that synchronizes the timing of digital circuits.
Clock rate
The frequency at which a clock signal oscillates, measured in hertz.
Positive-edge-triggered
Describing a digital component that only changes state when its clock signal transitions from low to high.