Sharp ER-A450T Service Manual - Page 22

2) Block diagram DATA BUS OPC1~USART OPC2 OPC1 BAUD RATE GENERATOR USART A USART B BAUD RATE GENERATOR USART C USART D USART Common input 3) Pin description Pin NO. Name 1 SL00 2 SL01 3 SL02 4 SL10 5 SL11 6 SL12 7 SL20 8 SL21 9 SL22 10 SL30 11 SL31 12 SL32 ER-A770 VCC GND GND GND GND GND GND GND GND GND GND GND 13 /CD0 /DCD1 14 BRK0 BRK1 15 TRNEMP0 TRENMP1 16 RCVRDY0 RCVRDY1 17 TRNRDY0 TRNRDY1 18 /CTS0 /CTS1 19 RCVDT0 20 VCC 21 GND 22 /CI0 RCVDT1 VCC GND /CI1 23 /RTS0 /RTS1 24 /CS0 /CS1 25 /CD1 /DCD2 I/O Description ISU RS-232/UNIT0 ISU channel select ISU ISU RS-232/UNIT1 ISU channel select ISU ISU RS-232/UNIT2 ISU channel select ISU ISU RS-232/UNIT3 ISU channel select ISU IS RS-232 control signal /CD input IS RS-232 break signal IS RS-232 transmission buffer empty signal IS RS-232 data reception enable signal IS RS-232 transmission enable signal IS RS-232 clear to send signal IS RS-232 reception data signal +5V GND IS RS-232 control signal /CI input O RS-232 request to send signal O RS-232 chip select signal IS RS-232 control signal /CD input Pin NO. Name 26 BRK1 27 TRNEMP1 28 RCVRDY1 29 TRNRDY1 30 /CTS1 31 RCVDT1 ER-A770 BRK2 TRENMP2 RCVRDY2 TRNRDY2 /CTS2 RCVDT2 32 /CI1 /CI2 33 /RTS1 /RTS2 34 /CS1 /CS2 35 /CD2 VCC 36 TRNEMP2 TRENMP3 37 RCVRDY2 RCVRDY3 38 TRNRDY2 TRNRDY3 39 CTS2Z /CTS3 40 RCVDT2 RCVDT3 41 /CI2 VCC 42 /CS2 /CS3 43 /CD3 /SINT 44 BRK3 45 TRNEMP3 46 RCVRDY3 47 TRNRDY3 48 /CTS3 49 RCVDT3 50 /CI3 GND GND GND GND GND GND GND 51 /CS3 /SRCS 52 D0 D0 53 D1 D1 I/O Description IS GND IS GND IS GND IS GND IS +5V IS RS-232 reception data signal IS RS-232 control signal /CI input O RS-232 request to send signal O RS-232 chip select signal IS +5V IS GND IS GND IS GND IS +5V IS GND IS +5V O NU IS RS-232: /CD, IN-LINE : /P1 IS GND IS GND IS GND IS GND IS GND IS GND IS GND O RS-232/INLINE chip select signal IO Data bus (CPU) IO Data bus (CPU) 4 - 14