INTRODUCTION
The ST7261, ST72P61 and ST72F61 devices are members of the ST7 microcontroller family designed for USB applications. All devices are based on a common industrystandard 8-bit core, featuring an enhanced instruction set.
The ST7261 ROM and ST72P61 FASTROM (Factory Advanced Service Technique ROM) devices are factory-programmed and are not reprogrammable.
The ST72F61 versions feature dual-voltage FLASH memory with In-Circuit Programming (ICP) capability.
Under software control, all devices can be placed in WAIT, SLOW, or HALT mode, reducing power consumption when the application is in idle or standby 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
   – 4K Program memory (ROM, FASTROM or Dual voltage FLASH) with read-write protection. In-Circuit programming for Flash versions
   – 256 bytes RAM memory (128-byte stack)
■ Clock, Reset and Supply Management
   – Enhanced Reset System (Power On Reset)
   – Low Voltage Detector (LVD)
   – Clock-out capability
   – 6 or 12 MHz Oscillator (8, 4, 2, 1 MHz internal freq.)
   – 3 Power saving modes: Halt, Wait and Slow
■ USB (Universal Serial Bus) Interface
   – DMA for low speed applications compliant with USB 1.5 Mbs specification (v 1.1) and USB HID specification (v 1.0):
   – Integrated 3.3V voltage regulator and transceivers
   – Suspend and Resume operations
   – 3 Endpoints
■ 11 I/O Ports
   – 11 multifunctional bidirectional I/O lines
   – Up to 7 External interrupts (2 vectors)
   – 8 high sink outputs (8mA@0.4 V/20mA@1.3)
■ 2 Timers
   – Configurable watchdog timer (8 to 500ms timeout)
   – 8-bit Time Base Unit (TBU) for generating periodic interrupts
■ Instruction Set
   – 8-bit data manipulation
   – 63 basic instructions
   – 17 main addressing modes
   – 8 x 8 unsigned multiply instruction
   – True bit manipulation
■ Development Tools
   – Full hardware/software development package