DS80C320/DS80C323 High-Speed/Low-Power Microcontrollers
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.
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