20-668-0024 Rabbit Semiconductor, 20-668-0024 Datasheet - Page 11

• Manufacturer Part Number: 20-668-0024
• Description: IC CPU RABBIT4000 128-LQFP
• Manufacturer: Rabbit Semiconductor

Specifications of 20-668-0024

• Processor Type: Rabbit 4000 8-bit
• Speed: 60MHz
• Voltage: 2.5V, 2.7V, 3V, 3.3V
• Mounting Type: Surface Mount
• Package / Case: 128-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Other names: 20-668-0022; 316-1078

1. T
R
4000 P
HE
ABBIT
ROCESSOR
1.1 Introduction
Rabbit Semiconductor was formed expressly to design a a better microprocessor for use in
small- and medium-scale single-board computers. The first microprocessors were the
Rabbit 2000 and the Rabbit 3000. The latest microprocessor is the Rabbit 4000. Rabbit
microprocessor designers have had years of experience using Z80, Z180, and HD64180
microprocessors in small single-board computers. The Rabbit microprocessors share a
similar architecture and a high degree of compatibility with these microprocessors, but
represent a vast improvement.
The Rabbit 4000 is a high-performance microprocessor with low electromagnetic interfer-
ence (EMI), and is designed specifically for embedded control, communications, and
Ethernet connectivity. The 8-bit Rabbit 4000 outperforms most 16–bit processors without
losing the efficiency of an 8–bit architecture. Extensive integrated features and glueless
architecture facilitate rapid hardware design, while a C-friendly instruction set promotes
efficient development of even the most complex applications.
The Rabbit 4000 is fast, running at up to 60 MHz, with compact code and support for up to
16 MB of memory. Operating with a 1.8 V core and 3.3 or 1.8 V I/O, the Rabbit 4000
boasts an internal 10Base-T Ethernet interface, eight channels of DMA, six serial ports with
IrDA, 40+ digital I/O, quadrature decoder, PWM outputs, and pulse capture and measure-
ment capabilities. It also features a battery-backable real-time clock, glueless memory and
I/O interfacing, and ultra-low power modes. Four levels of interrupt priority allow fast
response to real-time events. Its compact instruction set and high clock speeds give the
Rabbit 4000 exceptionally fast math, logic, and I/O performance.
1.2 Features
The Rabbit 4000 has several powerful design features that practically eliminate EMI prob-
lems, which is essential for OEMs that need to pass CE and regulatory radiofrequency
emissions tests. The amplitude of any electromagnetic radiation is reduced by the internal
spectrum spreader, by gated clocks (which prevent unnecessary clocking of unused regis-
ters), and by separate power planes for the processor core and I/O pins (which reduce
noise crosstalk). An auxiliary I/O bus can be used by designers to enable separate buses
for I/O and memory or to limit loading the memory bus to reduce EMI and ground bounce
problems when interfacing external peripherals to the processor. The auxiliary I/O bus
accomplishes this by duplicating the Rabbit's data bus on Parallel Port A, and uses Parallel
Chapter 1 The Rabbit 4000 Processor
1