GENERAL DESCRIPTION
EM73461B is an advanced single chip CMOS 4-bit micro-controller. It contains 4K/8K-byte ROM, 244-nibble RAM, 4-bit ALU, 13-level subroutine nesting, 22-stage time base, two 12-bit timer/counters for the kernel function. EM73461B also contains 6 interrupt sources, 1 input port, 2 bidirection ports, LCD display (32x4), and one high speed timer/counter with melody output.
EM73461B has plentiful operating modes (SLOW, IDLE, STOP) intended to reduce the power consumption.

FEATURES
• Operation voltage : 2.4V to 3.6V.
• Clock source : Dual clock system. Low-frequency oscillator is Crystal or RC oscillator (32K Hz,
   connect an external resistor) by mask option and high-frequency oscillator is RC
   oscillator (connect an external resistor), or built-in internal oscillator.
• Instruction set : 109 powerful instructions for 4K ROM / 107 powerful instructoins for 8K ROM.
• Instruction cycle time : 0.85µs for 9.2M or 1.7µs for 4.6M or 2µs for 4MHz. Selected by mask option (high
   speed clock).
   122 µs or 244µs by frequency double mask option for 32768 Hz (low speed clock).
• ROM capacity : 4096 X 8 bits / 8192 X 8 bits ROM are choosed by mask option.
• RAM capacity : 244 X 4 bits.
• Input port : 1 port (P0). P0(0..3) and IDLE releasing function are available by mask option.
• Bidirection port : 2 ports (P4, P8). P4.0 and SOUND is available by mask option. P4.1 is shared with
   HTC external input. P8(0..3) and IDLE releasing function are available by mask
   option.
• 12-bit timer/counter : Two 12-bit timer/counters are programmable for timer, event counter and pulse width
   measurement.
• High speed timer/counter : One 8-bit high speed timer/counters is programmable for auto load timer, melody
   output and pulse width measurement.
• Built-in time base counter : 22 stages.
• Subroutine nesting : Up to 13 levels.
• Interrupt : External . . . . . 2 input interrupt sources.
                   Internal . . . . . . 2 Timer overflow interrupts, 1 time base interrupt.
                                            1 high speed timer overflow interrupt.
• LCD driver : 32 X 4 dots, 1/4duty, 1/3duty, 1/2duty, static, 1/2 bias, 1/3 bias; 6 options selectable.
• Power saving function : SLOW, IDLE, STOP operation mode.
• Package type : Chip form 61 pins.

APPLICATIONS
   EM73461B is suitable for application in family applicance, consumer products, hand held games and the toy controller.