AIWA CDC-X227 Service Manual - Page 35

Pin No. 41 42 43 44 Pin Name TUN(R) CHG(R) AUX(R) RSELO I/O I Signal input pins. - Not used. I Signal inputs pins. O Input selector output pins. Description IC, LC75853NW Pin No. Pin Name I/O Description 1 S1 O LCD segment output. 2 S2 - Not used. 3 S3 O LCD segment output. 4 S4 - Not used. 5 ~ 35 36 ~ 40 S5 ~ S35 S36 ~ S40 - LCD segment output. - Not used. 41 ~ 43 COM1~ COM3 O LCD command driver output. 44 ~ 49 KS1 ~ KS6 O Key scan output. 50 ~ 52 KI1 ~ KI3 I Key scan input. These pins have build-in pull-down resistor. 53 ~ 54 KI4 ~ KI5 - Connected to GND. 55 TEST - Test pin. (Connected to GND.) 56 VDD - Power supply. Used for applying the LCD drive 2/3 bias voltage externally. (Must be connected to VDD2 when 57 VDD1 I a 1/2 bias drive scheme is used.) (Not used) Used for applying the LCD drive 1/3 bias voltage externally. (Must be connected to VDD1 when 58 VDD2 I a 1/2 bias drive scheme is used.) (Not used) 59 VSS - Power supply. (Connected to GND.) 60 OSC I/O Resistor and capacitor are attached externally form an oscillator circuit. 61 DO O Serial data interface pin; output data. 62 CE O Serial data interface pin; chip enable. 63 CL O Serial data interface pin; synchronization. 64 DI O Serial data interface pin; data transferred. - 35 -