DS80C320/DS80C323 High-Speed/Low-Power Microcontrollers

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80C32 COMPATIBILITY

The DS80C320/DS80C323 are CMOS 80C32-compatible microcontrollers designed for high

performance. In most cases, the devices will drop into an existing 80C32 design to significantly improve

the operation. Every effort has been made to keep the devices familiar to 8032 users, yet they have many

new features. In general, software written for existing 80C32-based systems will work on the DS80C320

and DS80C323. The exception is critical timing, because the high-speed microcontroller performs its

instructions much faster than the original. It may be necessary to use memories with faster access times if

the same crystal frequency is used.

Application Note 57: DS80C320 Memory Interface Timing is a useful tool to help the embedded system

designer select the proper memories for her or his application.

The DS80C320/DS80C323 run the standard 8051 instruction set and is pin compatible with an 80C32 in

any of three standard packages. They also provide the same timer/counter resources, full-duplex serial

port, 256 bytes of scratchpad RAM, and I/O ports as the standard 80C32. Timers will default to a 12

clock-per-cycle operation to keep timing compatible with original 8051 systems. However, they can be

programmed to run at the new 4 clocks per cycle if desired.

New hardware features are accessed using special-function registers that do not overlap with standard

80C32 locations. A summary of these SFRs is provided below.

The DS80C320/DS80C323 address memory in an identical fashion to the standard 80C32. Electrical

timing appears different due to the high-speed nature of the product. However, the signals are essentially

the same. Detailed timing diagrams are provided in the Electrical Specifications section.

This data sheet assumes the user is familiar with the basic features of the standard 80C32. In addition to

these standard features, the DS80C320/DS80C323 include many new functions. This data sheet provides

only a summary and overview. Detailed descriptions are available in the High-Speed Microcontroller

User’s Guide.