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