LM386是一种音频集成功放,具有自身功耗低、电压增益可调整、电源电压范围大、外接元件少和总谐波失真小等优点的功率放大器,广泛应用于录音机和收音机之中。
引脚2为反相输入端,3为同相输入端;引脚5为输出端;引脚6和4分别为电源和地;引脚1和8为电压增益设定端;使用时在引脚7和地
之间接旁路电容,通常取10μF。
汇编程序如下: - CCON EQU 0D8H
- CCF0 BIT CCON.0
- CCF1 BIT CCON.1
- CMOD EQU 0D9H
- CL EQU 0E9H
- CH EQU 0F9H
- CCAPM0 EQU 0DAH
- CCAP0L EQU 0EAH
- CCAP0H EQU 0FAH
- CR BIT CCON.6
- CF BIT CCON.7
- ORG 0000H
- LJMP MAIN
- ORG 000BH
- LJMP T0_INT
- ORG 003BH
- LJMP PCA_INT
- ORG 0100H
- MAIN:
- MOV SP,#64H
- MOV R1,#15
- MOV R7,#1AH
- MOV R6,#29H
- MOV TMOD,#01H
- MOV CCON,#0
- CLR A
- MOV CL,A
- MOV CH,A
- MOV CMOD,#02H
- MOV CCAP0L,R7
- MOV CCAP0H,R6
- MOV CCAPM0,#04DH
- MOV R0,#01H
- SETB CR
- SETB EA
- SETB ET0
- SETB TR0
- SJMP $
- T0_INT:
- DJNZ R1,T0_
- MOV R1,#15
- MOV A,R0
- RL A
- MOV DPTR,#TABLE
- MOVC A,@A+DPTR
- MOV R7,A
- MOV A,R0
- RL A
- INC A
- MOVC A,@A+DPTR
- MOV R6,A
- INC R0
- CJNE R0,#07H,T0_
- MOV R0,#00H
- T0_
- :
- RETI
- PCA_INT:
- PUSH PSW
- PUSH ACC
- CLR CCF0
- MOV A,CCAP0L
- ADD A,R7
- MOV CCAP0L,A
- MOV A,CCAP0H
- ADDC A,R6
- MOV CCAP0H,A
- POP ACC
- POP PSW
- RETI
- TABLE:
- DB1AH,29H,47H,25H,8FH,20H,0CCH,1EH,81H,1BH,0EAH,17H,9FH,15H
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