GENERAL DESCRIPTION
INTRODUCTION
The ST7263 Microcontrollers form a sub family of the ST7 dedicated to USB applications. The devices are based on an industry-standard 8-bit core and feature an enhanced instruction set. They operate at a 24MHz or 12 MHz oscillator frequency. Under software control, the ST7263 MCUs may be placed in either Wait or Halt modes, thus reducing power consumption. The enhanced instruction set and addressing modes afford real programming potential. In addition to standard 8-bit data management, the ST7263 MCUs feature true bit manipulation, 8x8 unsigned multiplication and indirect addressing modes. The devices include an ST7 Core, up to 16K program memory, up to 512 bytes RAM, 19 I/O lines and the following on-chip peripherals:
– USB low speed interface with 3 endpoints with programmable in/out configuration using the DMA architecture with embedded 3.3V voltage regulator and transceivers (no external components are needed).
– 8-bit Analog-to-Digital converter (ADC) with 8 multiplexed analog inputs
– industry standard asynchronous SCI serial interface (not on all products - see device summary below)
– digital Watchdog
– 16-bit Timer featuring an External clock input, 2 Input Captures, 2 Output Compares with Pulse Generator capabilities
– fast I2C Multi Master interface (not on all products - see device summary)
– Low voltage (LVD) reset ensuring proper power on or power-off of the device

All ST7263 MCUs are available in ROM and OTP versions.
The ST72E631 is the EPROM version of the ST7263 in CSDIP32 windowed packages.
A specific mode is available to allow programming of the EPROM user memory array. This is set by a specific voltage source applied to the VPP/TEST pin.

■ Up to 16Kbytes program memory
■ Data RAM: up to 512 bytes with 64 bytes stack
■ Run, Wait and Halt CPU modes
■ 12 or 24 MHz oscillator
■ RAM retention mode
■ USB (Universal Serial Bus) Interface with DMA
   for low speed applications compliant with USB
   1.5 Mbs specification (version 1.1) and USB
   HID specifications (version 1.0)
■ Integrated 3.3V voltage regulator and transceivers
■ Suspend and Resume operations
■ 3 endpoints with programmable in/out configuration
■ 19 programmable I/O lines with:
   – 8 high current I/Os (10mA at 1.3V)
   – 2 very high current pure Open Drain I/Os (25mA at 1.5V)
   – 8 lines individually programmable as interrupt inputs
■ Optional Low Voltage Detector (LVD)
■ Programmable Watchdog for system reliability
■ 16-bit Timer with:
   – 2 Input Captures
   – 2 Output Compares
   – PWM Generation capabilities
   – External Clock input
■ Asynchronous Serial Communications Interface
   (8K and 16K program memory versions only)
■ I2C Multi Master Interface up to 400 KHz
   (16K program memory version only)
■ 8-bit A/D Converter (ADC) with 8 channels
■ Fully static operation
■ 63 basic instructions
■ 17 main addressing modes
■ 8x8 unsigned multiply instruction
■ True bit manipulation
■ Versatile Development Tools (under Windows)
   including assembler, linker, C-compiler,
   archiver, source level debugger, software
   library, hardware emulator, programming
   boards and gang programmers