高级计算机体系结构设计及其在数据中心和云计算的应用Lecture 3Main Memory and DRAM Technology
高级计算机体系结构设计及其在数据中心和云计算的应 用 Lecture 3 Main Memory and DRAM Technology
高级计算机体系结构设计及其在数据中心和云计算的应用SRAM VS. DRAMSRAM = StaticRAM- As long as power is present, data is retainedDRAM=DynamicRAM- If you don't do anything, you lose the dataSRAM: 6T per bit- built with normal high-speed CMos technologyDRAM: 1T per bit (+1 capacitor)- built with special DRAM process optimized for density
高级计算机体系结构设计及其在数据中心和云计算的应 用 SRAM vs. DRAM • SRAM = Static RAM – As long as power is present, data is retained • DRAM = Dynamic RAM – If you don’t do anything, you lose the data • SRAM: 6T per bit – built with normal high-speed CMOS technology • DRAM: 1T per bit (+1 capacitor) – built with special DRAM process optimized for density
高级计算机体系结构设计及其在数据中心和云计算的应用Hardware StructuresSRAMDRAMwordlinewordlinebbb
高级计算机体系结构设计及其在数据中心和云计算的应 用 Hardware Structures b b SRAM wordline b DRAM wordline
高级计算机体系结构设计及其在数据中心和云计算的应用Implementing the Capacitor (1/2)You can use a “dead" transistor gate:But this wastes area becausewenowhavetwotransistorsCapacitorM,wordlineAndthe“dummy"transistormayneedDiffusedto bebiggertohold enoughchargebit linePolysiliconPolysiliconplategate
高级计算机体系结构设计及其在数据中心和云计算的应 用 Implementing the Capacitor (1/2) • You can use a “dead” transistor gate: But this wastes area because we now have two transistors And the “dummy” transistor may need to be bigger to hold enough charge
高级计算机体系结构设计及其在数据中心和云计算的应用Implementing the Capacitor (2/2)There are other advanced structuresCell Plate Si"Trench Cell"CapInsulatorReflling PolyStorageNodePolySi SubstrateField Oxide
高级计算机体系结构设计及其在数据中心和云计算的应 用 Implementing the Capacitor (2/2) • There are other advanced structures “Trench Cell” Cell Plate Si Cap Insulator Storage Node Poly Field Oxide Refilling Poly Si Substrate