Yamaha A-S2000 Service Manual - Page 31

I IC DATA IC502: M38039xxxxx (FRONT P.C.B.) Single chip 8-bit microprocessor Main clock input XIN 30 Main clock output XOUT 31 Sub-clock Sub-clock input output XCIN XCOUT 28 29 Clock generating circuit RAM ROM VSS VCC 32 1 Data bus MICROPROCESSOR A X Y S PCH PCL PS A-S2000 Reset input RESET 27 CNVSS 26 Prescaler 12 (8) Timer 1 (8) Timer 2 (8) CNTR0 CNTR1 CNTR2 Prescaler X (8) Prescaler Y (8) Timer X (8) Timer Y (8) Timer Z (16) A/D converter (10) PWM (8) SI/O2 (8) SI/O1 (8) D/A D/A converter converter 2 (8) 1 (8) SI/O3 (8) P6 (8) INT3 P5 (8) P4 (8) INT00 INT1 INT2 INT40 P3 (8) P2 (8) P1 (8) INT01 INT41 P0 (8) 23 VREF AVSS 4 5 6 7 8 9 10 11 I/O port P6 12 13 14 15 16 17 18 19 I/O port P5 20 21 22 23 24 25 28 29 I/O port P4 57 58 59 60 61 62 63 64 I/O port P3 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 I/O port P2 (LED drive) I/O port P1 49 50 51 52 53 54 55 56 I/O port P0 64 THM_R 63 HP_PRDR 62 HP_PRDL 61 EX_DI 60 PRV1 59 AVSS 58 VREF 57 VCC 56 RY_PHONO 55 RY_MMMC 54 RY_BYP 53 RY_DIR 52 EV_MT 51 EV2_DA 50 EV2_CL 49 EV2_CE THM_L 1 PRD_R 2 PRD_L 3 RY_SPA 4 RY_SPB 5 /ICEX 6 /CSEX 7 EV1_CE 8 EV1_CL 9 EV1_DA 10 EX_DI 11 232_RTS 12 232_CTS 13 232_TXD 14 232_RXD 15 RY_PWR 16 M38039xxxxx 48 PSVA1 47 PSVA2 46 EXAD 45 MODEL 44 EXCL 43 4051C 42 4051B 41 4051A 40 STBY_CNT 39 REM 38 EXDT 37 MVOL+ 36 MVOL35 RY_HP 34 RY_UNBAL 33 RY_BAL_GAIN A-S2000 PWR_DET 17 CNVSS 18 /RESET 19 PRI_R 20 PRI_L 21 XIN 22 XOUT 23 VSS 24 LED_PWR 25 RY_CD 26 RY_TU 27 RY_L1 28 RY_L2 29 MUTE_PRE 30 MUTE_REC 31 RY_BAL 32 31