User`s manual

Rabbit 4000 Designer’s Handbook rabbit.com 7
1. Introduction
This manual is intended for the engineer designing a system using the Rabbit 4000 microprocessor and
Rabbit’s Dynamic C development environment. It explains how to develop a system that is based on the
Rabbit 4000 and can be programmed with Dynamic C.
With Rabbit 4000 microprocessors and Dynamic C, many traditional tools and concepts are obsolete.
Complicated and fragile in-circuit emulators are unnecessary. EPROM burners are not needed. Rabbit
4000 microprocessors and Dynamic C work together without elaborate hardware aids, provided that the
designer observes certain design conventions.
For all topics covered in this manual, further information is available in the Rabbit 4000 Microprocessor
User’s Manual.
1.1 Summary of Design Conventions
Rabbit-based systems should be designed using the following conventions:
• Include a programming connector.
• Connect a static RAM having at least 128 KB to the Rabbit 4000 using /CS1, /OE1 and /WE1.
• Connect a flash memory that is on the approved list and has at least 128 KB of storage to the Rabbit
4000 using /CS0, /OE0 and /WE0.
• Install a crystal oscillator with a frequency of 32.768 kHz to drive the battery-backable clock. (Battery-
backing is optional, but the clock is used in the cold boot sequence to generate a known baud rate of
2400 bps.)
• Install a crystal or oscillator for the main processor clock that is a multiple of 614.4 kHz, or better, a
multiple of 1.8432 MHz.
• Do not use pin PB1 in your design if cloning is to be used.
• Be sure unused inputs are not floating.