GENERAL DESCRIPTION
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 performances that the two methodologies allow.
ST52x400/440/441 is produced by STMicroelectronics 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.

Memories
■ Up to 8 Kbytes EPROM/OTP
■ 128/256 bytes of RAM
■ Readout Protection

Core
■ Register File Based Architecture
■ 55 instructions
■ Hardware multiplication and division
■ Decision Processor for the implementation of
   Fuzzy Logic algorithms

Clock and Power Supply
■ Up to 20 MHz clock frequency.
■ On-chip Power On Reset (POR) and Brown Out
   Detector (BOD)
■ Power Saving features

Interrupts
■ 6 interrupt vectors
■ Top Level External Interrupt (INT)

I/O Ports
■ 13 or 21 I/O PINs configurable in Input and
   Output mode
■ High current sink/source in all pins. Triac Driver
   output can supply 50 mA

Peripherals
■ Programmable 8-bit Timer/PWMs with internal
   16-bit Prescaler featuring:
   – PWM output
   – Input capture
   – Output compare
   – Pulse generator mode
■ Watchdog timer
■ 6-channels Analog Comparator with 16-bit
   Timer (not available in ST52T400)
■ Triac/PWM Driver Timer with zero crossing
   detector and high current capability for:
   – PWM mode
   – Burst Mode
   – Phase Angle Partialization mode