The DDR4 SDRAM is a high-speed dynamic random-access memory internally configured as sixteen-banks,2 bank group with 4 banks for each bankgroup for x16 DRAM.
The DDR4 SDRAM uses an 8n-prefetch architecture to achieve high-speed operation. The 8n-prefetch architecture is combined 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 DDR4 SDRAM consists of a single 8n-bit wide, four-clock data transfer at the internal DRAM core and two corresponding n-bit wide, one-half-clock-cycle data transfers at the I/O pins.