INTRODUCTION
The ST72F324 devices are members of the ST7 microcontroller family designed for the 5V operating range.

– The 32-pin devices are designed for mid-range
   applications
– The 42/44-pin devices target the same range of
   applications requiring more than 24 I/O ports.

For a description of the differences between ST72F324 and ST72F324B devices refer to Section 14.3 on page 152 All devices are based on a common industry standard 8-bit core, featuring an enhanced instruction set and are available with FLASH program memory.
Under software control, all devices can be placed in WAIT, SLOW, ACTIVE-HALT or HALT mode, reducing power consumption when the application is in idle or stand-by state.
The enhanced instruction set and addressing modes of the ST7 offer both power and flexibility to software developers, enabling the design of highly efficient and compact application code. In addition to standard 8-bit data management, all ST7 microcontrollers feature true bit manipulation, 8x8 unsigned multiplication and indirect addressing modes.

■ Memories
   – 8 to 32K dual voltage High Density Flash (HD
      Flash) with read-out protection capability. In
      Application Programming and In-Circuit Programming for HDFlash devices
   – 384 to 1K bytes RAM
   – HDFlash endurance: 100 cycles, data retention: 20 years at 55°C
■ Clock, Reset And Supply Management
   – Enhanced low voltage supervisor (LVD) for
      main supply with programmable reset thresh
      olds and auxiliary voltage detector (AVD) with
      interrupt capability
   – Clock sources: crystal/ceramic resonator os
      cillators, internal RC oscillator, clock security
      system and bypass for external clock
   – PLL for 2x frequency multiplication
   – Four Power Saving Modes: Halt, Active-Halt,
      Wait and Slow
■ Interrupt Management
   – Nested interrupt controller
   – 10 interrupt vectors plus TRAP and RESET
   – 9/6 external interrupt lines (on 4 vectors)
■ Up to 32 I/O Ports
   – 32/24 multifunctional bidirectional I/O lines
   – 22/17 alternate function lines
   – 12/10 high sink outputs
■ 4 Timers
   – Main Clock Controller with: Real time base,
      Beep and Clock-out capabilities
   – Configurable watchdog timer
   – 16-bit Timer A with: 1 input capture, 1 output
      compare, external clock input, PWM and
      pulse generator modes
   – 16-bit Timer B with: 2 input captures, 2 output
   compares, PWM and pulse generator modes
■ 2 Communication Interfaces
   – SPI synchronous serial interface
   – SCI asynchronous serial interface
■ 1 Analog Peripheral (low current coupling)
   – 10-bit ADC with up to 12 robust input ports
■ Instruction Set
   – 8-bit Data Manipulation
   – 63 Basic Instructions
   – 17 main Addressing Modes
   – 8 x 8 Unsigned Multiply Instruction
■ Development Tools
   – Full hardware/software development package
   – In-Circuit Testing capability