adc_10bits.a51

ateml 10位AD 通用程序

$INCLUDE   (t89c51cc01.INC)
msb_value_converted DATA 10H;    /* converted msb value */
lsb_value_converted DATA 11H;    /* converted lsb value */
msb_value_AN6 DATA 12H;          /* converted msb AN6 value */
lsb_value_AN6 DATA 13H;          /* converted lsb AN6 value */
msb_value_AN7 DATA 14H;          /* converted msb AN7 value */
lsb_value_AN7 DATA 15H;          /* converted lsb AN7 value */
end_of_convertion BIT 20H;       /* software flag */
CLR end_of_convertion

org 000h
ljmp begin

org 43h
ljmp adc_it

;/**
; * FUNCTION_PURPOSE:this function setup Adc with channel 6 and 7 and start 
; * 8bits convertion.
; * FUNCTION_INPUTS:void
; * FUNCTION_OUTPUTS:void
; */
org 0100h
begin:

/* configure channel P1.6(AN6) and P1.7(AN7) for ADC */
MOV ADCF,#0C0h;

;/* init prescaler for adc clock */
;/* Fadc = Fperiph/(2*(32-PRS)), PRS -> ADCLK[4:0] */
MOV ADCLK,#06h;                  /* Fosc = 16 MHz, Fadsc = 153.8khz */

MOV ADCON,#20h;                  /* Enable the ADC */


SETB EA;                         /* enable interrupts */
SETB EADC;                       /* enable ADC interrupt */
loop:

   ANL ADCON,#~07h;              /* Clear the channel field ADCON[2:0] */
   ORL ADCON, #06h;              /* Select channel 6 */
   ANL ADCON,#~40h;              /* standard mode */
   ORL ADCON, #08h;              /* Start conversion */

   JNB end_of_convertion,$;      /* wait end of convertion */
   CLR end_of_convertion;        /* clear software flag */
   MOV msb_value_AN6,msb_value_converted;/* save converted msb value */
   MOV lsb_value_AN6,lsb_value_converted;/* save converted lsb value */


   ANL ADCON,#~07h;              /* Clear the channel field ADCON[2:0] */
   ORL ADCON, #07h;              /* Select channel 7 */
   ANL ADCON,#~40h;              /* standard mode */
   ORL ADCON, #08h;              /* Start conversion */

   JNB end_of_convertion,$;      /* wait end of convertion */
   CLR end_of_convertion;        /* clear software flag */
   MOV msb_value_AN7,msb_value_converted;/* save converted msb value */
   MOV lsb_value_AN7,lsb_value_converted;/* save converted lsb value */

JMP loop

;/**
; * FUNCTION_PURPOSE:Adc interrupt, save ADDH and ADDL into an unsigned int
; * FUNCTION_INPUTS:void
; * FUNCTION_OUTPUTS:void
; */
adc_it:
ANL ADCON,#~10h;                 /* Clear the End of conversion flag */
;/* copy ADDH[7:6] into msb_value_converted[1:0] */
MOV A,ADDH
SWAP A
RR A
RR A
ANL A,#~0FCh
MOV msb_value_converted,A
;/* copy ADDH[5:0] into lsb_value_coverted[7:2]
MOV A,ADDH
RL A
RL A
ANL A,#~03h
MOV lsb_value_converted,A
;/* copy ADDL[1:0] into lsb_value_coverted[1:0]
MOV A,ADDL
ANL A,#~0FCh
ORL lsb_value_converted,A

SETB end_of_convertion;          /* set flag */
RETI

end