INTRODUCTION
The ST7SCR and ST7FSCR devices are members of the ST7 microcontroller family designed for USB applications. All devices are based on a common industry-standard 8-bit core, featuring an enhanced instruction set.

■ Memories
    – Up to 16K of ROM or High Density Flash (HDFlash) program memory with read/write protection, HDFlash In-Circuit and In-Application Programming. 100 write/erase cycles guaranteed, data retention: 20 years at 55°C
    – Up to 768 bytes of RAM including up to 128 bytes stack and 256 bytes USB buffer
■ Clock, Reset and Supply Management
    – Low Voltage Reset
    – 2 power saving modes: Halt and Wait modes
    – PLL for generating 48 MHz USB clock using a 4 MHz crystal
■ Interrupt Management
    – Nested Interrupt Controller
■ USB (Universal Serial Bus) Interface
    – 256-byte buffer for full speed bulk, control and interrupt transfer types compliant with USB specification (version 2.0)
    – On-Chip 3.3V USB voltage regulator and transceivers with software power-down
    – 7 USB Endpoints: One 8-byte Bidirectional Control Endpoint One 64-byte In Endpoint, One 64-byte Out Endpoint Four 8-byte In Endpoints
■ 35 or 4 I/O ports:
    – Up to 4 LED outputs with software programmable constant current (3 or 7 mA).
    – 2 General purpose I/Os programmable as interrupts
    – Up to 8 line inputs programmable as interrupts
    – Up to 20 Outputs
    – 1 line assigned by default as static input after reset
■ ISO7816-3 UART Interface:
    – 4 Mhz Clock generation
    – Synchronous/Asynchronous protocols (T=0, T=1)
    – Automatic retry on parity error
    – Programmable Baud rate from 372 clock pulses up to 11.625 clock pulses (D=32/F=372)
    – Card Insertion/Removal Detection
■ Smartcard Power Supply:
    – Selectable card VCC 1.8V, 3V, and 5V
    – Internal Step-up converter for 5V supplied Smartcards (with a current of up to 55mA) using only two external components.
    – Programmable Smartcard Internal Voltage Regulator (1.8V to 3.0V) with current overload protection and 4 KV ESD protection (Human Body Model) for all Smartcard Interface I/Os
■ One 8-bit Timer
    – Time Base Unit (TBU) for generating periodic interrupts.
■ Development Tools
    – Full hardware/software development package