8051 MCU WITH SUPERFLASH

The FlashFlex51 microcontroller family from Silicon Storage Technology is a series of 8051-compatible MCUs with SuperFlash technology. It's designed as an alternative to one-time programmable or non-programmable read-only memory-based MCU products. The FlashFlex51 family will integrate up to 68K of flash memory array, which uses a small sector size for both code and data storage.

SuperFlash
SuperFlash technology is a NOR type, split-gate cell architecture, which uses a thick-oxide process. The architecture facilitates a simple design suitable for high performance, high-reliability, small or medium sector size, in- or off-system programming, and a variety of densities.

The products
The FlashFlex51 family includes three devices: the SST89C54, the SST89C58, and the SST89C59, embedding 20K, 36K, and 68K of SuperFlash EEPROM, respectively. SST has developed an architecture for the FlashFlex51 family whereby the flash memory is mapped into two independent banks. A primary memory bank of 16K, 32K, and 60K of SuperFlash EEPROM, respectively, with 128 bytes sector size, occupies the internal ROM space for an 8051-compatible MCU. The secondary memory bank of 4K of SuperFlash EEPROM with 68 bytes sector size can be used as either electronically erasable data storage or code storage. This dual memory bank architecture allows for an In-Application Programming mode that allows the CPU to run user programs from one bank while concurrently servicing a flash programming operation in the background on the other bank.

In-application programming
The FlashFlex51 family offers advantages in the area of "on-the-fly" concurrent programming and operation. By incorporating an EEPROM-like fast write time, and a small-sector architecture that segments the flash memory into two SuperFlash banks, the FlashFlex51 family devices can enter the in-application programming mode. In this mode, new program code is downloaded to one bank of the flash memory while the MCU continues to function, running active user code out of the other flash bank, thereby performing its intended operation. One block may also be used to replace an external EEPROM data memory, due to the small-sector architecture of Super-Flash, simplifying system design and reducing parts count.

Other features
A special security protection mode called SoftLock prevents both accidental overwriting of program memory and software piracy. The FlashFlex51 offers a 100-year data retention and an endurance of at least 10,000 program/erase cycles. Additional specifications include: 256 bytes of register/data RAM; external support of up to 68K program/data memory; three 16-bit timers/counters; programmable UART; configurable watchdog timer; extended power-saving modes (idle, standby, power down, wake-up); 3V (± 10%) operation to 12MHz and 5V (± 10%) operation to 33MHz; six interrupt sources and two priority levels; four eight-bit I/O ports; and PDIP-40, PLCC-44, and TQFP-44 packages.

Third-party support
SST also announced the availability of a range of third-party development tools and environments. Included are programmers, emulators, C compilers, assemblers, and evaluation kits.

Companies providing hardware programmers include: Advantech, Advin, EE Tools, Hi-Lo, Leap, Needham, Phyton, Stag, and System General. EDI Corp. and Emulation Technology provide programming adapters for the FlashFlex51. Suppliers of software tools such as compilers, assemblers, and simulators include Hi-Tech, Keil, and Tasking. HiTex, MetaLink, Nohau, and Phyton provide in-circuit emulators. Phytec provides evaluation kits.

Pricing and availability
The SST89C54, the SST89C58, and the SST89C59 are priced in high-volume production quantities at $4.85, $6.18, and $8 each, respectively. The 'C54 and 'C58 are available now, and the 'C59 will be available later this year.

Silicon Storage Technology
Sunnyvale, CA
(408) 735-9110
www.sst.com

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