INTRODUCTION
The ST7HUB is a USB microcontroller based on ST7 core, which is an enhanced industry-standard architecture. The USB module of the ST7HUB is a compound device, consisting of a 3-port HUB and an attached embedded function. To the USB host, the embedded function appears as an attached port of the HUB with its own device address and endpoints.

■ Memories
   – 32K High Density Flash (HD-Flash) program memory with read/write protection or 16K ROM
   – In-Application Programming (IAP) via USB and In-Circuit programming (ICP) for Flash device
   – 768 bytes RAM memory including up to 176 bytes for USB buffers and up to 256 bytes stack
■ Clock, Reset and Supply Management
   – Enhanced Reset System (Power On Reset) and Low Voltage Detector (LVD) on some devices
   – PLL for generating 48 MHz USB clock using a 4 MHz crystal
   – Up to 12 MHz internal frequency on ROM device
   – Up to 8 MHz internal frequency on Flash device
   – Clock-out capability
   – 2 Power saving modes
■ USB HUB Function
   – 3 bus-powered downstream ports (1 connected internally to embedded function)
   – Individual downstream Power Switching
   – Overcurrent Protection for each downstream
   – Supports all USB Standard and HUB commands
   – Integrated 3.3V voltage regulator and transceivers
■ USB Full Speed Function
   – 7 USB Endpoints:
      One 8-byte Bidirectional Control Endpoint
      One 64-byte In Endpoint (Interrupt or Bulk)
      One 64-byte Out Endpoint (Interrupt or Bulk)
      Four 8-byte In Endpoints (Interrupt)
   – DMA for Full speed applications compliant with USB specification (v 2.0) – Suspend and Resume operations
■ 35 I/O Ports
   – 35 multifunctional bidirectional I/O lines
   – 23 individually selectable external interrupts (3 vectors) with per port programmable sensitivity
   – Pull up resistors in input individually selectable by software
   – 3 ports (20 I/Os) can be individually configured to open drain pull up configuration for PS/2 and keyboard function.
   – 7 high sink outputs (8 mA@0.4 V/20 mA@1.3 V)
■ 3 Timers
   – Configurable watchdog timer (8 to 500 ms timeout)
   – 8 bit Time Base Unit (TBU) for generating periodic interrupts, cascadable with ART
   – 8 bit Auto-Reload Timer (ART) with 2 Input Captures, 2 PWM outputs and External Clock Input
■ Analog Peripheral
   – 10-bit A/D Converter with VREF+ and VREF- reference pins 4 high impedance high accuracy channels 12 standard channels
■ 1 Communication Interface
   – Serial Peripheral Interface (SPI)
■ Instruction Set
   – 8-bit data manipulation
   – 63 basic instructions
   – 17 main addressing modes
   – Nested Interrupts
   – 8 x 8 unsigned multiply instruction
   – True bit manipulation
■ Development Tools
   – Full hardware/software development package
■ Operating Conditions
   – 4.0 to 5.25V power supply
   – 0 to 70°C temperature range