Presentation on theme: "Confidential Nov. 21, 2003 - 1 - Chip Enable Don’t Care NAND – Enabling Higher Performance, High Density NAND Flash Memory for Cellular Handset Applications."— Presentation transcript:
Confidential Nov. 21, Chip Enable Don’t Care NAND – Enabling Higher Performance, High Density NAND Flash Memory for Cellular Handset Applications Toshiba America Electronic Components, Inc. November 2003
Confidential Nov. 21, Chip Enabled “Don’t Care” NAND Modified NAND Flash for easier integration in cell phones or other CE devices with complex memory subsystems. Targeted to address growing file storage requirements in cell phones Conventional NAND flash requires that the chip enable signal line be asserted low during the entire read cycle which prevents the processor from communicating with other devices on the same bus Chip Enable “Don’t Care” NAND flash allows the microprocessor to communicate with other devices on the bus such as SRAM, PSRAM or NOR flash while the NAND retrieves the information requested. Enables easier integration of NAND with NOR, SRAM and PSRAM in a system Initially available in 128Mb (TC581282AXB) and 256Mb (TC582562AXB) densities (.16 micron). New part numbers after die shrink to 0.13 micron in Q are TC58DDM82A1 (256Mb, 1.8V core and I/O) and TC58DDM82A1 (256Mb, dual power 2.5V to 3.6V for V CC and 1.65V to 1.85V for V CCQ ). CEDC feature also now available in large block NAND in densities of 1Gb and 2Gb
Confidential Nov. 21, MCP Memory Subsystem Trend Conventional “ Talk-only ” Cell phones used NOR + SRAM for code storage, backup and data storage memory requirements As cell phone applications have increased, the need for increased data storage for music, photo and data storage, as well as additional software application storage has made NAND Flash more attractive because of its faster program and erase times, higher density and smaller cell size. Chip Enable Don ’ t Care NAND makes NAND flash much easier to combine with NOR and other types of memory in memory subsystems (or multi-chip packages) with multiple types of memory CEDC NAND can be used in conventional cell phone architectures which combine NOR+SRAM+NAND or in newer NAND + low power SDRAM architectures. NOR+SRAM+NAND MCP solutions are rapidly gaining in acceptance among cell phone manufacturers
Confidential Nov. 21, NAND Flash Read Function Options A Sequential Read (1) (00H) M N Start-address input Busy 00H /CE /WE /RE R/B I/O Data Output Type-1 (TSOP Package) Sequential Read Type-2 (BGA/MCP Package) Chip Enable Don’t Care M N Start-address input Busy 00H /CE /WE /RE R/B I/O Data Output Cell array Select page N M Figure 3. Read mode (1) operation 527 Next Add. Input No Sequential Read /CE don’t care Sequential Read
Confidential Nov. 21, High Speed Low Power Large Density Low Cost High Speed program Large Density High Speed Low Cost Low Power 64M-128M32M-64M16M RAM 4M-8M 8M-16M Flash PSRAM LP SDRAM LP-SRAM NOR 8M-16M 16M-32M 8M-16M 64M-128M Movie / Music Buffer Working Area Data Backup 128M-512M 128M-512M Movie / Music App. Soft Storage 128M-256M 128M-256M Boot & Basic Program Talk only Browse phone 3G Talk only Browse phone 3G NAND MCP Memory Requirements for Cellular Phones
Confidential Nov. 21, Application Trend and Onboard Memory Size Memory size is increased by diversity of application.
Confidential Nov. 21, Multi-Chip Package for Mobile Phone Demand of large density RAM and Flash. Increase of various application High-speed requirement for execution of application software (PSRAM/NOR) Embedded High-Density NAND (128M/256M/512M +) High-Density Pseudo SRAM (32M/64M/128M) Low cost solution MCP SolutionDemand from Mobile Phone Market ＋ Multi-chip packages combine a complete, complex memory subsystem in a single, small component High-Speed Function (PSRAM/NOR) 8Page Mode: 25ns→18ns Burst Mode 15ns
Confidential Nov. 21, Conventional solution Code : NOR Work: Pseudo-SRAM Data: NAND Backup: SRAM (in Japanese market) Architectures for next generation phones Cost oriented solution Code & Data: NAND Work: LP-SDRAM with burst mode with shadowing architecture
Confidential Nov. 21, NAND+NOR+RAM SDRAM+NAND NOR ＋ RAM MP/Y From 2003, NAND becoming popular in Europe and US (already popular in Asia) driven by storage requirements Production volume CY Mobile MCP Memory Trend Source: Toshiba Internal Data/Projections 2001 < 10% Camera Phones End 2005 > 90% Camera Phones
Confidential Nov. 21, Trend of Multi-Chip Package Package Area balls (Actual 56balls) (16MS+64MF) (8/4MS+64/32MF) Stacked MCP 3/4Chip St-MCP (NAND+NOR+PSRAM) 0.8mm pitch 9x x x Small Small form factor 3Chip 9x (4MS+32MF) (SRAM+NOR) 7x10 (NOR+NOR+SRAM+PSRAM) 7 x 10 9 x 12 CY 1.2 9x x Chip 3Chip more /6Chip St-MCP 9x Chip over 9x12
Confidential Nov. 21, NAND vs. NOR - Cell Structure Word line Bit line Source line Unit Cell Contact ５ Ｆ ２Ｆ 10F 2 NOR Cell size ２Ｆ ２Ｆ ２Ｆ 4F 2 NAND Source line Word line Unit Cell Layout Cross- section Cell Array
Confidential Nov. 21, Performance comparison NAND 2LCNAND 4LC Read Prog. Erase 27MB/s 8.3MB/s 1.5ms 25us+50nsx1056 for 2k bytes 50nsx µs for 2k bytes 128 Kbytes 20.5MB/s 50us+50nsx1056 for 2k bytes 1.7MB/s 50nsx ms for 2k bytes 2ms 128 Kbytes NOR 4LC 1.2s 128 Kbytes 50.MB/s 85ns+25nsx3 for 8 bytes 0.145MB/s 440µs for 64 bytes NOR 2LC 2s 64 Kbytes 55.2MB/s 80ns+30nsx7 for 16 bytes 0.15MB/s 107µs for 16 bytes
Confidential Nov. 21, Summary Memory requirements in high-end cell phones have increased dramatically to support new applications Different types of memory are best suited for different applications –Code storage –Working memory –File and additional application storage Multi-chip packages (MCP) enable complex memory subsystems in a single component Traditional NOR +SRAM memory solutions for cell phones are being replaced by NOR+PSRAM+NAND and other combinations of multiple memories One newer low-cost alternative is NAND + Low Power SDRAM Chip Enable Don’t Care NAND Flash makes integration of NAND with other memory types much easier.
Confidential Nov. 21, Information in this presentation, including product pricing and specifications, and content of services is current on the date issued, but is subject to change without prior notice. All trademarks and tradenames held within are the properties of their respective holders.