This LSI is an 8-bit RISC type microprocessor with high speed CMOS technology and low power consumption. Integrated onto a single chip are on chip watchdog timer (WDT), Data RAM, ROM, programmable real time clock counter, internal/external interrupt, power down mode, LCD driver, infrared transmitter function, and tri-state I/O. The EM78468 provides a seven option bits to accommodate user’s requirements.

Features

CPU

• Operating voltage and temperature range:
  * 1.9V ~ 5.5 V. (at 0℃~+70℃)
• Operation speed: DC ~ 10MHz clock input.
• Dual clock operation
  * High frequency oscillator can select among Crystal, RC, or PLL (phase lock loop)
  * Low frequency oscillator can select between Crystal or RC mode
• Totally 272 bytes SRAM
  * 144 bytes general purpose register
  * 128 bytes on chip data RAM
• 4K * 13 bits MASK - ROM
• Up to 28 bi-directional tri-state I/O ports
  * Typically, 12 bi-directional tri-state I/O ports.
  * 16 bi-directional tri-state I/O ports shared with LCD segment output pin.
• 8-level stack for subroutine nesting
• 8-bit real time clock/counter (TCC)
• One infrared transmitter/PWM generator function
• Four sets of 8 bits auto reload timer can be used as interrupt sources
  * Counter 1: independent down-count timer.
  * Counter 2, High Pulse Width Timer (HPWT), and Low Pulse Width Timer
  (LPWT) shared with IR function.
• Programmable free running on chip watchdog timer (WDT). This function can operate on Normal, Green and Idle mode.
• Operation modes:
  * Normal mode: The CPU operated on frequency of main oscillator (Fm)
  * Green mode: The CPU operated on frequency sub-oscillator (Fs) and main oscillator (Fm) stop.
  * Idle mode: CPU idle, LCD display remains working
  * Sleep mode: whole chip stop working.
• Input port wake up function (PORT6, PORT8). Working on Idle and sleep mode.
• Eight interrupt sources, three external and five internal.
  * Internal interrupt source : TCC; Counter 1,2; High/Low pulse width timer.
  * External interrupt source : INT0, INT1 and Pin change wake-up (Port 6 and Port 8)
• Packages:
  * Dice form : 59 pin
  * QFP-64 pin : EM78468Q (Body 14mm*20mm)
  * LQFP-64 pin : EM78468AQ (Body 7mm*7mm)
  * LQFP-44 pin : EM78468BQ (Body 10mm*10mm)
  * QFP-44 pin : EM78468CQ (Body 10mm*10mm)

LCD Circuit

• Common driver pins: 4
• Segment driver pins: 32
• LCD Bias: 1/3, 1/2 bias
• LCD Duty: 1/4, 1/3, 1/2 duty

• Remote control for air conditioner
• Health care
• Home appliances