ST52T400 Datasheet, PDF (7/94 Pages) STMicroelectronics – 8-BIT INTELLIGENT CONTROLLER UNIT ICU Timer/PWM, Analog Comparator, Triac/PWM Timer, WDG

ST52T400/T440/E440/T441
1 GENERAL DESCRIPTION
1.1 Introduction
ST52x400/440/441 are 8-bit Intelligent Control
Units (ICU) of the ST Five Family, which are able
to perform both boolean and fuzzy algorithms in
an efficient manner, in order to reach the best per-
formances that the two methodologies allow.
ST52x400/440/441 is produced by STMicroelec-
tronics using the reliable high performance CMOS
process, including integrated-on-chip peripherals
that allow maximization of system reliability,
decreasing system costs and minimizing the
number of external components.
The flexible I/O configuration of ST52x400/440/
441 allows for an interface with a wide range of
external devices, like D/A converters or power
control devices.
ST52x400/440/441 pins are configurable, allowing
the user to set the input or output signals on each
single pin.
A hardware multiplier (8 bit by 8 bit with 16 bit
result) and divider (16 bit over 8 bit with 8 bit
result and 8 bit remainder) is available to imple-
ment complex functions by using a single instruc-
tion, optimizing program memory utilization and
computational speed.
Fuzzy Logic dedicated structures in ST52x400/
440/441 ICU’s can be exploited to model complex
sys
tems with high accuracy in a useful and easy way.
Fuzzy Expert Systems for overall system manage-
ment and fuzzy Real time Controls can be
designed to increase performances at highly com-
petitive costs.
The linguistic approach characterizing Fuzzy
Logic is based on a set of IF-THEN rules, which
describe the control behavior, as well as on Mem-
bership Functions, which are associated to input
and output variables.
Up to 334 Membership Functions, with triangular
and trapezoidal shapes, or singleton values are
available to describe fuzzy variables.
The TIMER/PWM peripheral allows the manage-
ment of power devices and timing signals, imple-
menting different operating modes and high
frequency PWM (Pulse With Modulation) controls.
Input Capture and Output Compare functions are
available on the TIMER.
The programmable Timer has a 16 bit Internal
Prescaler and an 8 bit Counter. It can use internal
or external START/STOP signals and clock.
An internal programmable WATCHDOG is avail-
able to avoid loop errors and to reset the ICU.
An Analog Comparator with a 6 channel multi-
plexer is available on ST52x440/441 family
devices. This analog peripheral allows easy imple-
mentation of a high resolution A/D conversion. By
using only an external capacitor this peripheral
may be configured in order to achieve up to 12 bit
A/D converter resolution. It includes a 2.5 V band-
gap reference for A/D conversion calibration,
which can be used externally for signal condition-
ing.
An on-chip TRIAC driver peripheral allows the
direct management of power devices, implement-
ing two different operating modes: Burst Mode
(i.e. Thermal Applications), Phase Angle Partial-
ization (i.e. Motors Control by Triacs). The TRIAC
Driver also generates a PWM signal.
The ST52x400/440/441 family also includes an
on-chip Power-on-Reset (POR), which provides
an internal chip reset during power up situation
and a Brown-Out Detector (BOD), which resets
the ICU if the voltage source V_DD dips below a
minimum value.
In order to optimize energy consumption, two dif-
ferent power saving modes are available: Wait
mode and Halt mode.
Program Memory (EPROM/OTP) addressing
capability addresses up to 8 Kbytes of memory
locations to store both program instructions and
permanent data.
EPROM can be locked by the user to prevent
external undesired operations.
Operations may be performed on data stored in
RAM, allowing the direct combination of new input
and feedback data. All bytes of RAM are used like
Register File.
OTP (One Time Programmable) version devices
are fully compatible with the EPROM windowed
version, which may be used for prototyping and
pre-production phases of development.
A powerful development environment consisting
of a board and software tools allows an easy con-
figuration and use of ST52x400/440/441.
The VISUAL FIVE^TM software tool allows devel-
opment of projects through a user-friendly graphi-
cal interface and optimization of generated code.
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