The devices are Flash Memory LED control with USB type 8-bit high performance RISC architecture microcontrollers, designed for applications that interface directly to analog signals and require a USB interface.

For memory features, the Flash Memory offers users the convenience of multi-programming features. Other memory includes an area of RAM Data Memory as well as an area of true EEPROM memory for storage of non-volatile data such as serial numbers, calibration data, etc.

Analog feature includes two comparators which only exist in the HT68FB541 device. Two timer/ event counters are provided for external event counting, time interval/pulse width measurement or an accurate time base generation. There are also multiple 8-bit PWM outputs specially provided for multiple LED applications. Communication with the outside world is catered for by including fully integrated SPI and USB interface functions, two popular interfaces which provide designers with a means of easy communication with external peripheral hardware. Protective features such as an internal Watchdog Timer, Low Voltage Reset and Low Voltage Detector coupled with excellent noise immunity and ESD protection ensure that reliable operation is maintained in hostile electrical environments. The external interrupts can be triggered with rising edge, falling edge or both falling and rising edges.

A full choice of internal high and low oscillators is provided including two fully integrated system oscillators which require no external components for their implementation. The ability to operate and switch dynamically between a range of operating modes using different clock sources gives users the ability to optimise microcontroller operation and minimise power consumption.

The inclusion of flexible I/O programming features along with many other features ensures that these devices will find specific excellent use in PC peripheral applications such as LED mouse, LED key pad, LED gaming keyboard, etc.

The devices are fully supported by the Holtek range of fully functional development and programming tools, providing a means for fast and efficient product development cycles.

CPU Features

• Operating voltage:
  • VDD (MCU):   
    •  fSYS =12MHz: 3.0V~5.5V
  • VDD (USB mode):
    •  fSYS = 6MHz/12MHz: 3.0V~5.5V
    •  fSYS = 16MHz: 3.3V~5.5V
• Up to 0.25us instruction cycle with 16MHz system clock at VDD =5V
• Power down and wake-up functions to reduce power consumption
• Oscillator types
  • Internal High Speed 12MHz RC – HIRC
  • Internal Low Speed 32kHz RC – LIRC
• Multi-mode operation: NORMAL, SLOW, IDLE and SLEEP
• Fully integrated internal oscillators require no external components
• All instructions executed in 1~3 instruction cycles
• Table read instructions
• 115 powerful instructions
• 8-level subroutine nesting
• Bit manipulation instruction

Peripheral Features

• Flash Program Memory: 4K×16~8K×16
• Data Memory: 256×8~512×8
• LED Memory: 128×8 – for HT68FB571 only
• USB Memory: 64×8
• True EEPROM Memory: 64×8
• Watchdog Timer function
• Two Comparator functions – for HT68FB541 only
• Up to 41 bidirectional I/O lines
• Dual pin-shared external interrupts
• Dual Time Base functions for generation of fixed time interrupt signals
• Two 16-bit Timer/Event Counters with PFD (Programmable Frequency Divider) functions
• Multiple 8-bit PWM outputs for LED application
• USB interface
  • USB 2.0 Full Speed compatible
  • 4 endpoints supported including endpoint 0
  • All endpoints except endpoint 0 can support interrupt and bulk transfer
  • All endpoints except endpoint 0 have a fixed FIFO size of 16, 32 and 64 bytes respectively
  • Endpoint 0 support control transfer
  • Endpoint 0 has 8 byte FIFO
  • Support 3.3V LDO and internal UDP 1.5kΩ pull-up resistor
  • Internal 12MHz RC oscillator with 0.25% accuracy for all USB modes
• Single Serial Peripheral Interface – SPI
• In Application Programming function – IAP
• In System Programming function – ISP
• Low voltage reset function
• Low voltage detect function
• Package types: 24/28-pin SSOP, 48-pin LQFP

Specification:

• max. frequency: 16MHz
• VDD: 3.0V~5.5V
• program memory: 8Kx16
• data memory: 512x8
• data EEPROM: 64x8
• stack: 8
• I/O: 41
• timer: 16-bit×2
• ADC: -
• interface: SPI×1
• case: 28SSOP