The EM78M680 is a series of 8-bit Universal Serial Bus, RISC architecture, Multi-Time Programming (MTP) microcontrollers. It is specifically designed for USB full speed device application. The EM78M680 also supports one device address and five endpoints.
The EM78M680 has eight-level stack and four sets of interrupt sources. It has a maximum of 36 General Input/Output pins with the capacity of sinking large current. Each device has 271 bytes of general purpose SRAM, 6K bytes of program ROM, and is embedded with 32 bytes of EEPROM.
These series of ICs have special features that meet user’s requirements. Such features are:

• Dual Clock mode which allows the device to run on very low power.
• Pattern Detect Application function which is used in serial transmission to count waveform width
• Pulse Width Modulation that can generate a duty-cycle-programmable signal
• 24-channel AD converter with up to 10 bits resolution

Features

• Operating voltage: 4.4V ~ 5.25V
• USB Specification Compliance
  * Universal Serial Bus Specification Version 1.1
  * USB Device Class Definition for Human Interface Device (HID), Firmware Specification Version 1.1
  * Supports one device address and five endpoints
• USB Application
  * P74 (D+) has an internal pull-high resistor (1.5KW)
  * USB protocol handling
  * USB device state handling
  * Identifies and decodes Standard USB commands to Endpoint Zero
• Built-in 8-bit RISC MCU
  * 8-level stacks for subroutine nesting, and interrupt
  * 4 sets of interrupts
  * 8-bit real time clock/counter (TCC) with overflow interrupt
  * Built-in RC oscillator free running for Watchdog Timer and Dual clock mode
  * Two independent programmable prescalers for WDT and TCC
  * Two methods of power saving:
  * Power-down mode (Sleep mode)
  * Dual clock mode
  * Two clocks per instruction cycle
  * Multi-time programmable
• Set 1 INT : (jump to 0x08)
  * TCC overflow interrupt
  * EP0 command in interrupt
  * USB suspend interrupt
  * USB reset interrupt
  * USB HOST resume interrupt
• Set 2 INT : (jump to 0x10)
  * RF1 low pattern interrupt
  * RF1 high pattern interrupt
  * RF2 low pattern interrupt
  * RF2 high pattern interrupt
• Set 3 INT : (jump to 0x18)
  * P77 port change interrupt
  * P76 port change interrupt
  * Timer 1 comparator completed interrupt
• Set 4 INT : (jump to 0x20)
  * EP1~5 output Endpoint received O.K interrupt
• I/O Ports
  * 3 LED sink pins
  * Each GPIO pin in Ports 5, 6, 8, P90~P93, P95, P96, P70~P72 and P76~P77,
  has an internal programmable pull-high resistor (25 KW)
  * Each GPIO pin of Port 6, P76~P77, and Port 9 can wakeup the MCU from sleep
  mode by input state change
• Internal Memory
  * Built-in 6K´13 bits Program ROM
  * Built-in 271 bytes general purpose registers (SRAM)
  * Built-in USB Application FIFOs
  * Built-in 32 bytes E2PROM
• Operation Frequency
  * Normal Mode: MCU runs on an external oscillator frequency of 4MHz, Internal
  system frequency of 8MHz, 16MHz or 24MHz
  * Dual Clock Mode: MCU runs at a frequency of 256kHz (or 32kHz, 4kHz, 500Hz),
  using an internal oscillator with an external crystal resonator turned off to save power
• Built-in Pattern Detecting Application for serial signal transmission
• Built-in Pulse Width Modulation (PWM)
  * 2 channels PWM function on P.92 (PWM1) and P.93 (PWM2)
  * 8-bit resolution of PWM output
  * 8 selections of duty cycles
• Built-in 24-Channel Analog-to-Digital Converter (ADC)
  * Built-in AD Converter with 10-bit resolution
  * 4 types of ADC clock source selection: 256K/128K/64K/32K
• Built-in 3.3V Voltage Regulator
  * For UDC power supply
  * Pull-up source for the external USB resistor on D+ pin
• Package Type
  * 44-pin QFP (EM78M680 (A/D) AQ)
  * 40-pin DIP 600mil (EM78M680 (A/D) AP)
  * 24-pin DIP 600mil (EM78M680 (A/D) CP)
  * 24-pin SOP 300mil (EM78M680 (A/D) CM)
  * 20-pin DIP 300mil (EM78M680 (A/D) BP)
  * 20-pin SOP 300mil (EM78M680 (A/D) BM)