(No.RA011)1-132.4.5 Control CircuitThe MCU carries out the following tasks:(1) Controls the FM IC (IC501).(2) Controls the baseband IC (IC709).(3) Controls the PLL (IC2) & TX/RX outputs.(4) Controls IO expender through I2C level converter.(5) Controls the display unit.Fig.8 Control circuit2.4.5.1 Memory CircuitThe transceiver has an 256k-bit EEPROM (IC716). The EE-PROM contains adjustment data. The MCU (IC714) controls theEEPROM through three serial data lines.Fig.9 Memory circuit2.4.5.2 Display CircuitThe MCU (IC714) controls the Display 7-segment LED andLEDs.When power is on, the MCU will use the MBL line to control thekey backlight LEDs.When the transceiver is busy, the GLED line goes high, Q1 turnson and the green LED (D23) lights after Q4 turn on. In transmitmode, the RLED line goes high, Q2 and Q8 turns on and the redLED (D23) lights.BLED will be set high when the function select (FPU setting) ison, Q6 turn on and the blue LED (D22) lights.The dimmer function is controlled by the switch Q5. The LEDdriver (IC1) controls the functions of the 7-segment LED throughthe LEDI, LECE, LECL, LELH lines from the MCU.Fig.10 Dsplay circuitBLEDC.DATAR.DATASCLKIRQCSNIC700 IC702Display unitIC1LED DriverIC714MCUIC709BasebandICIC501FM ICRLEDGLEDMBLLECILECELECLLELHIC2PLL ICPLL_UPLL_CLKPLL_DATAPLL_LEPLL_PDN2PDNRSTNCSNSCLKSDATAI2 C levelconverterIOexpenderEEP_DATAOEEP_CLKEEP_DATAIEEP_CSEEP_WPIC716EEPROMIC714MCUQ4SWQ3SWQ5SWD1~D5Key backlightDisplay7-segmentIC714MCUIC1LEDdriverLEDILEDMLECELECLLELHMBLQ1SWQ7SWD23GLEDQ2SWQ8SWRLEDQ6SWD22BLED
