Rev. 1.71
106
April 11, 2017
Rev. 1.71
107
April 11, 2017
HT66F002/HT66F0025/HT66F003/HT66F004
Cost-Effective A/D Flash MCU with EEPROM
HT66F002/HT66F0025/HT66F003/HT66F004
Cost-Effective A/D Flash MCU with EEPROM
A/D Programming Examples
The following two programming examples illustrate how to setup and implement an A/D conversion.
In the first example, the method of polling the ADBZ bit in the SADC0 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,0BH
mov
S
ADC1,a ; select f
SYS
/8 as A/D clock and switch off the bandgap reference voltage
set
ENADC
mov a,03h
; setup
PASR to configure pin AN0
mov
PASR
,a
mov a,20h
mov
S
ADC0,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
ADBZ
; poll the
S
ADC0 register
ADBZ
bit to detect end of A/D conversion
jmp polling_EOC
; continue polling
mov a,
SADO
L ; read low byte conversion result value
mov
SADOL_buffer,a ; save result to user defined register
mov a,
SADO
H ; read high byte conversion result value
mov
SADOH_buffer,a ; save result to user defined register
:
:
jmp start_conversion ; start next a/d conversion
