HT46R01B/02B/01N/02N
HT48R01B/02B/01N/02N
Example: using an EOCB polling method to detect the end of conversion
clr ADE
mov a,00000001B
mov ACSR,a
mov a,00000100B
mov ADCR,a
:
; disable ADC interrupt
; select fSYS/8 as A/D clock and ADONB=0
; setup ADCR register to configure Port as A/D inputs
; and select AN0 to be connected to the A/D converter
:
Start_conversion:
clr START
set START
clr START
Polling_EOC:
; reset A/D
; start A/D
sz
EOCB
; poll the ADCR register EOCB bit to detect end
; of A/D conversion
; continue polling
; read low byte conversion result value
; save result to user defined register
; read high byte conversion result value
; save result to user defined register
jmp polling_EOC
mov a,ADRL
mov adrl_buffer,a
mov a,ADRH
mov adrh_buffer,a
:
jmp start_conversion
; start next A/D conversion
Note: To power off ADC module, it is necessary to set ADONB as ²1².
Example: using the interrupt method to detect the end of conversion
clr ADE
mov a,00000001B
; disable ADC interrupt
mov ACSR,a
mov a,00000100B
mov ADCR,a
:
; select fSYS/8 as A/D clock and ADONB=0
; setup ADCR register to configure Port as A/D inputs
; and select AN0 to be connected to the A/D
:
Start_conversion:
clr START
set START
clr START
clr ADF
set ADE
set EMI
; reset A/D
; start A/D
; clear ADC interrupt request flag
; enable ADC interrupt
; enable global interrupt
:
:
:
; ADC interrupt service routine
ADC_:
mov acc_stack,a
mov a,STATUS
mov status_stack,a
:
; save ACC to user defined memory
; save STATUS to user defined memory
:
mov a,ADRL
mov adrl_buffer,a
mov a,ADRH
mov adrh_buffer,a
:
; read low byte conversion result value
; save result to user defined register
; read high byte conversion result value
; save result to user defined register
:
EXIT_ISR:
mov a,status_stack
mov STATUS,a
mov a,acc_stack
clr ADF
; restore STATUS from user defined memory
; restore ACC from user defined memory
; clear ADC interrupt flag
reti
Note: To power off ADC module, it is necessary to set ADONB as ²1².
Rev.1.10
48
February 12, 2010
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
