Icom ID-51A Service Manual - Page 18

• CPU (LOGIC UNIT: IC5) (continued) Pin No. Line Name Description I/O J13 IOEN Expander chip enable. O J15 DCSFT DSP clock shift control. L=+600 Hz shifted. O J2 BPLLSTB PLL serial strobe. (Band B) O Interrupt detection from the real J4 RTC_IRQ time clock IC. I L=Alerm detected. K1 ANOISE Noise level detection. (Band A) H=Noise signal is detected. I K13 BAFMUTE RX AF mute control. (Band B) L=Mute. O Modulation signal line (DV/FM) K14 D_AS switching control. H=While transmitting in the DV O mode. 2nd IF filter (digital/analog) switch- K15 DAFS ing control. H=While receiving in the DV O mode. CI-V bus line communication sta- K2 EBUSY tus detection. I L=Busy. K3 IOSTB1 Expander serial strobe. O L1 R3C R3 line control. L=While recieiving. O L12 SQL SQL key input. L=Pushed. I L13 BNOISE Noise level detection (Band B). H=Noise signal is detected. I L14 PSC 5VS power supply line control. L=While in the power save mode. O L15 3VC 3VS power supply line control. H=Power ON. O Modulation signal line switching L2 PLAY control. O H=Recorded audio is transmitted. AM ʢAir bandʣreceive circuit L3 BAM power control. L=While receiving in the AM O mode. M1 DASTB1 D/A converter serial strobe. O M12 TX232 UART data (RS-232C). (4800/9600/38400 bps) O M14 ESIO EEPROM serial data. I/O M15 T3C Transmit circuit power control. H=While transmitting. O M2 CLOUT CI-V/CLONE UART data. (300-38400 bps) O M5 DSP_STB DSP serial strobe. O M6 DSPC DSP power control. H=DSP is ON. O Receive circuit power control. M7 AR3C (Band A) O L=While receiving on band A. M8 LCDRS LCD driver serial data. O M9 LCDCS LCD driver chip select. O N1 CLIN CI-V/CLONE UART (300-38400 bps) data. I GPS module operating mode N12 G_HIB (Normal/Sleep) switching control. O L=While in the sleep mode. Pin No. Line Name Description I/O N15 ECK EEPROM serial clock. O N2 SD_SENC microSD card insert detection. L=Inserted. I N3 SD_TXD Serial data to the attached microSD card. O N4 DSP_SI DSP serial data. I N6 RTC_SDA Serial data to/from the clock IC. real time I/O N7 APLLSTB PLL serial strobe. (Band A) O N9 LCDDT LCD driver serial data. O P1 SD_CS Chip select to the attached microSD card. O P12 GPSC GPS module power control. H=Power ON. O P13 RX232 RS-232C UART (4800/9600 bps) data. I P14 INTPTT [PTT] key input. L=Pushed. I P2 SD_SCK Serial clock to the attached microSD card. O P4 DSP_CK DSP serial clock. O P5 DSP_PD DSP power down control. H=Power down. O P6 LCDRES LCD driver reset. L=Reset. O R1 SD_RXD Serial data from the attached microSD card. I R13 AFON AF AMP power control. O R14 EXTPTT External PTT input. I R2 DSP_SO DSP serial data. O R5 DSP_RESET DSP reset control. L=Reset. O R6 RTC_SCL Serial clock to the real time clock IC. O R8 LCDCK LCD driver serial clock. O 4 - 9