DS5000FP.pdf

DESCRIPTION
The DS5000FP Soft Microprocessor Chip is an 8051-compatible processor based on NV RAM
technology. It is substantially more flexible than a standard 8051, yet provides full compatibility with the
8051 instruction set, timers, serial port, and parallel I/O ports. By using NV RAM instead of ROM, the
user can program and then reprogram the microcontroller while in-system. The application software can
even change its own operation, which allows frequent software upgrades, adaptive programs, customized
systems, etc. In addition, by using NV SRAM, the DS5000FP is ideal for data-logging applications and it
connects easily to a Dallas real-time clock for time stamp and date.
The DS5000FP provides the benefits of NV RAM without using I/O resources. It uses a nonmultiplexed
byte-wide address and data bus for memory access. This bus can perform all memory access and provides
decoded chip enables for SRAM. This leaves the 32 I/O port pins free for application use. The DS5000FP
uses ordinary SRAM and battery backs the memory contents with a user’s external lithium cell. Data is
maintained for over 10 years with a very small lithium cell. A DS5000FP also provides crash-proof
operation in portable systems or systems with unreliable power. These features include the ability to save
the operating state, Power-fail Reset, Power-fail Interrupt, and Watchdog Timer.