Description

The W742C810 is a high-performance 4-bit microcontroller (mC) that provides an LCD driver. The device contains a 4-bit ALU, two 8-bit timers, two dividers (for two oscillators) in dual-clock operation, a 40 ´ 4 LCD driver, six 4-bit I/O ports (including 1 output port for LED driving), and one channel DTMF generator. There are also five interrupt sources and 8-level subroutine nesting for interrupt applications. The W742C810 operates on very low current and has one power reduction mode, that is the dual-clock slow operation, which helps to minimize power dissipation.

Specifications and features

• Operating voltage: 2.4V-3.6V
• Dual-clock operation
• Main oscillator: Connect to 3.58 MHz crystal only
• Sub-oscillator: Connect to 32768 Hz crystal only
• Memory:
  • 8192 x 16 bit program ROM (including 32K x 4 bit look-up table)
  • 1024 x 4 bit data RAM (including 16 nibbles x 16 pages working registers)
  • 40 x 4 LCD data RAM
• 24 input/output pins:
  • Port for input only: 1 port/4 pins
  • Input/output ports: 3 ports/12 pins
  • High sink current output port for LED driving: 1 port /4 pins
  • Port for output only: 1 port/ 4 pins
• Power-down mode:
  • Hold function: no operation (main oscillator and sub-oscillator still operate)
  • Stop function: no operation (only main oscillator stops but sub-oscillator still operates)
  • Dual-clock slow mode: system is operated by the sub-oscillator (FOSC = Fs and Fm is stopped)
• Five types of interrupts:
  • Four internal interrupts (Divider0, Divider1, Timer 0, Timer 1)
  • One external interrupt (RC Port)
• LCD driver output:
  • 40 segments x 4 commons
  • 1/4 duty 1/3 bias driving mode
  • Clock source should be the sub-oscillator clock in the dual-clock operation mode
• MFP output pin:
  • Output is software selectable as modulating or nonmodulating frequency
  • Works as frequency output specified by Timer 1
• DTMF output pin: Output is one channel Dual Tone Multi-frequency signal for dialling
• Two built-in 14-bit frequency dividers:
  • Divider0: the clock source is the output of the main oscillator
  • Divider1: the clock source is the output of the sub-oscillator
• Two built-in 8-bit programmable countdown timers:
  • Timer 0: one of two internal clock frequencies (FOSC/4 or FOSC/1024) can be selected
  • Timer 1: with auto-reload function, and one of three internal clock frequencies (FOSC, FOSC/64 or Fs) can be selected by MR1 register; the specified frequency can be delivered to MFP pin
• Built-in 18/15-bit watchdog timer selectable for system reset; enable the watch dog timer or not is determined by code option
• Powerful instruction set: 131 instructions
• 8-level subroutine (include interrupt) nesting

Application Scenarios

The W742C810 microcontroller is suitable for various applications, including but not limited to:

• Consumer electronics
• Industrial automation
• Home appliances
• Communications

Comparison

• High-performance 4-bit microcontroller.
• Provides an LCD driver.
• Low current consumption.
• Dual-clock operation for power reduction.
• Multiple built-in timers and dividers.
• Supports interrupt applications.

• Limited memory capacity.
• Only supports specific crystal frequencies for the main and sub oscillators.
• Not suitable for complex applications requiring higher bit count.