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Rev. 2.50
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Rev. 2.50
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HT66F20/HT66F30/HT66F40/HT66F50/HT66F60
HT66FU30/HT66FU40/HT66FU50/HT66FU60
A/D Flash MCU with EEPROM
HT66F20/HT66F30/HT66F40/HT66F50/HT66F60
HT66FU30/HT66FU40/HT66FU50/HT66FU60
A/D Flash MCU with EEPROM
A/D Programming Example
The following two programming examples illustrate how to setup and implement an A/D conversion.
In the first example, the method of polling the EOCB bit in the ADCR0 register is used to detect
when the conversion cycle is complete, whereas in the second example, the A/D interrupt is used to
determine when the conversion is complete.
Example: using an EOCB polling method to detect the end of conversion
clr
ADE
;
disable
ADC
interrupt
mov a,03H
mov ADCR1,a ; select f
SYS
/8 as A/D clock and switch off 1.25V
clr ADOFF
mov a,0Fh ; setup ACERL and ACERH to configure pins AN0~AN3
mov ACERL,a
mov a,00h
mov ACERH,00h ; ACERH is only for HT66F60
mov a,00h
mov ADCR0,a ; enable and connect AN0 channel to A/D converter
:
start_conversion:
clr START ; high pulse on start bit to initiate conversion
set START ; reset A/D
clr START ; start A/D
polling_EOC:
sz EOCB ; poll the ADCR0 register EOCB bit to detect end of A/D conversion
jmp polling_EOC ; continue polling
mov a,ADRL ; read low byte conversion result value
mov ADRL_buffer,a ; save result to user defined register
mov a,ADRH ; read high byte conversion result value
mov ADRH_buffer,a ; save result to user defined register
:
:
jmp start_conversion ; start next a/d conversion