DDR3L SDRAM Alliance Memory DDR3L SDRAM uses a double data rate architecture to achieve high-speed operation. The double data rate architecture is an 8n-prefetch architecture with an interface designed to transfer two data words per clock cycle at the I/O pins. A single read or write operation for the DDR3 SDRAM effectively consists of a single 8n-bit-wide, four-clock-cycle data transfer at the internal DRAM core and eight corresponding n-bit-wide, one-half-clock-cycle data transfers at the I/O pins.