Introduction - Semtech SH3000 User Manual

1. Introduction

The programmable SH3000 MicroBuddy™ (µBuddy™) provides all mandatory microcontroller support
functions:
· CPU Supervisor
· Clock Management System
· Real-Time Support
· Auxiliary functions
Three components make a complete system: any microcontroller, the SH3000, and a bypass capacitor.
This low-cost system would consume very little power and have clock-frequency accuracy of ±0.5%. A
fourth component, a 32.768 kHz watch crystal, raises the clock frequency accuracy to ± 0.0256% (± 256
ppm).
The SH3000 can operate completely stand-alone, or under control of the microcontroller. A single-wire
interface handles both bi-directional communications and the interrupt / wake-up signal from the SH3000.
The SH3000 stores all configuration, calibration, parameters, and status information in a 36-byte bank of
control registers. On reset, most of these are reloaded with defaults from the factory-set One-Time-
Programmable (OTP) memory. The microcontroller can change any settings on the fly. If some of the
settings must remain fixed, a comprehensive set of write-protect bits is provided for several related groups
of registers (with both permanent write-inhibit and lock/unlock capabilities).
A backup power source may also be connected to the SH3000. The IC can directly accommodate 2/3-cell
zinc-carbon/alkaline, 2/3-cell mercury, 2/3/4-cell NiCd/NiMH, 1-cell Li/Li+ batteries, or a super cap.
SH3000UM version 0.95
Copyright ©2002 Semtech Corporation
2002-08
SH3000 User Manual
Preliminary
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