DS5000FP

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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 non-multiplexed

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

crashproof 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.

A user loads programs into the DS5000FP via its on-chip Serial Bootstrap Loader. This function

supervises the loading of code into NV RAM, validates it, then becomes transparent to the user. Software

can be stored in an 8-kbyte or 32-kbyte CMOS SRAM. Using its internal Partitioning, the DS5000FP will

divide this common RAM into user programmable code and data segments. This Partition can be

selected at program loading time, but can be modified anytime later. It will decode memory access to the

SRAM, communicate via its Byte-wide bus and write-protect the memory portion designated as ROM.

Combining program and data storage in one device saves board space and cost. The DS5000FP can also

access a second 32 kbytes of NV RAM but this area is restricted to data memory. For a user that wants a

pre-constructed module using the DS5000FP, RAM, lithium cell, and optional real time clock; the

DS2250(T) and DS5000(T) are available and described in separate data sheets. More details are also

contained in the User’s Guide section of the Secure Microcontroller Data Book.

ORDERING INFORMATION

The following devices are available as standard products from Dallas Semiconductor:

PART #

DESCRIPTION

DS5000FP-16

80-pin QFP, Max. clock speed 16 MHz, 0

° to 70°C operation

Operating information is contained in the User’s Guide section of the Secure Microcontroller Data Book.

This data sheet provides ordering information, pin-out, and electrical specifications.