This section deals with hardware explanation of the Project..

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Microcontroller : PIC 16F877

  • High performance RISC CPU(8 bit)
  • 35 single word instructions
  • Operating speed: DC – 20 MHz clock input
  • Up to 8K x 14 words of FLASH Program Memory,
  • Up to 368 x 8 bytes of Data Memory (RAM)            
  • Up to 256 x 8 bytes of EEPROM Data Memory
  • Interrupt capability (up to 14 sources)
  • Low power, high speed CMOS FLASH/EEPROM technology
  •  In-Circuit Serial Programming(ICSP) via two pins
  • Single 5V In-Circuit Serial Programming capability
  • In-Circuit Debugging via two pins
  • Wide operating voltage range: 2.0V to 5.5V
  • High Sink/Source Current: 25 mA
  • Low-power consumption:

                         0.6 mA typical @ 3V, 4 MHz  

                        20 ìA typical @ 3V, 32 kHz

                       1 A typical standby current

  • 10-bit multi-channel Analog-to-Digital converter (8 channel ADC)
  • Synchronous Serial Port (SSP) with SPI(Master mode) and I2C (Master/Slave)
  • Universal Synchronous Asynchronous Receiver Transmitter (USART/SCI) with 9-bit address detection
  • Parallel Slave Port (PSP) 8-bits wide, with External RD, WR and CS controls.


  • 3 Timers

                  Timer0: 8-bit timer/counter with 8-bit pre-scalar
                  Timer1: 16-bit timer/counter with pre-scalar
                  Timer2: 8-bit timer/counter with 8-bit period
                                 register, prescaler/ postscaler

  • Two Capture, Compare, PWM modules

                 Capture is 16-bit, max. resolution is 12.5 ns  
                 Compare is 16-bit, max. resolution

  • 33 I/O Ports


Voice Recognition IC: HM2007

  • Single Chip Voice Recognition CMOS LSI
  • Maximum 40 words can be recognized for one chip
  • Maximum 1.92 Sec of word can be recognized
  • Direct Microphone connection
  • Two Control Modes: Manual Mode/CPU Mode
  • Response time: Less than 300ms
  • Power Supply 5V
  • 48-Pin DIP, 52 Pin PLCC, 48 pad bare chip
  • External 64K SRAM
  • External
    Crystal Oscillator: 3.58MHz
  • On-chip Analog front end, Voice Analysis, Recognition and System control functions



      Voice Recognition Circuit on breadboard

                        (for Testing)


64K High Speed CMOS SRAM: HM6264      

      • Low-power standby        

           — 0.1 mW (typ)            — 10 μW (typ)    

     • Low power operation— 15 mW/MHz (typ)    

     • Fast access time— l00/120/150 ns (max)     


       • Single +5 V supply    

    • Completely static memory 

             — No clock or timing strobe required 

    • Equal access and cycle time   

    • Common data input and output, three-state output    

    • Directly TTL compatible— All inputs and outputs  

   • Battery back up operation capability    














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