Renesas - Next-Generation 1.1 Gb Low-Latency, High-Speed Memory Devices with Low Power Consumption for Networking Equipment

The volume of network traffic continues to grow rapidly, especially with the widespread adoption of media-rich smartphones, digital media players, and internet-enabled digital cameras. To process this traffic smoothly, data equipment on the network, such as switches and routers, are required to process increasingly larger amount of data per-unit time.

As a result, there is growing demand for increased capacity and faster speeds, not only in the buffer memory used to hold this data temporarily within network equipment, but also in the table memory used to assign transfer destinations to this data. Furthermore, reducing the power consumption of network equipment to help achieve ecological goals on a global scale is now seen as extremely important and thus there are increasing needs for reduced power consumption in the memory used in this equipment.

To address these needs, Renesas Electronics has developed new memory devices that achieve higher capacities and speeds, while at the same time reducing power consumption by taking advantage of its unique process and circuit technologies.

The main functions of the memory devices are as follows.

(1) Higher capacities and speeds as well as reduced power consumption achieved through Renesas Electronics' 40 nanometer (nm) embedded DRAM (eDRAM) technology.

The new network memory devices are based on Renesas Electronics’ 40-nm eDRAM technology and the company’s circuit technologies resulting from its development of high-speed memory devices. As a result, compared to the company’s existing low-latency DRAM products, Renesas Electronics’ new network memory devices achieve quadrupled memory capacity of 1.1 Gb, 30 percent improved random-cycle performance of 13.3 nanoseconds (ns) for high-speed data read and write operations, and double the maximum operating frequency of 800 megahertz (MHz). Despite these improvements, the power consumption is kept down to a low 2 watts (W).

(2) High-speed interface with high reliability

The operating frequency of the new Renesas Electronics’ network memory devices has increased from 400 to 800 MHz, compared to the existing Renesas Electronics memory device. To operate the 800-MHz DDR (double data rate) interface for the 36-bit data input/output (I/O) in a stable manner, the company has reduced the voltage of the I/O circuits supporting a power supply of 1.0 V and adopted high-side termination, which has a proven track record in graphics memory devices, to stabilize operations. The new network memory devices provide a variety of functions that assure operational reliability, starting with programmable on-die termination, which integrates on-chip termination devices for the input-signal pins. These functions also include a data inversion function that reduces noise at data output, a per-bit deskew function that end-product manufacturers can use to adjust signal input and output timings on an individual signal-pin basis, and a mirroring function that can easily control the wiring lengths when clam-shell mounting is used on the printed circuit board.

(3) Package that features the same structure and similar size as the existing product

Due to the increased operating frequency, Renesas Electronics increased the power-supply pin count to 38 pins in a package with the same structure as the 11 x 18.5 millimeter (mm) package used with the existing product, but was still able to hold the package size down to 14 x 18.5 mm. Since the new products are provided in a package that already has proven reliability in the industry, system designers who adopt the new products can build reliable systems without facing problems concerning electrical characteristics in the printed circuit-board design phase.