ADCON:MOV DPTR, # 0F0FFH gated ADC0809 channel 0

MOV A, # 00H channel 0 = 00H channel 1 = 0 1h- channel 7 = 07H.

MOVX @DPTR，A； Start analog-to-digital conversion

Here: JNB P3.3, here; Judge whether the data conversion is completed, and wait if it is not.

MOVX A，@ DPTR； Read the converted data

MOV 20H，A； The voltage value on the thermistor at the current temperature read from ADC0809 is stored in units of 20H.

RET