HT46R12A Holtek Semiconductor Inc., HT46R12A Datasheet - Page 25

• Manufacturer Part Number: HT46R12A
• Description: Ht46r12a -- A/d Type 8-bit Otp Mcu
• Manufacturer: Holtek Semiconductor Inc.

Example: using interrupt method to detect end of conversion
Start_conversion:
; ADC interrupt service routine
ADC_ISR:
EXIT_INT_ISR:
Rev. 1.00
clr
mov
mov
mov
mov
clr
set
clr
clr
set
set
mov
mov
mov
mov
mov
mov
mov
clr
set
clr
mov
mov
mov
reti
EADI
a,00000001B
ACSR,a
a,00100000B
ADCR,a
:
:
START
START
START
ADF
EADI
EMI
:
:
:
acc_stack,a
a,STATUS
status_stack,a
:
:
a,ADRH
adrh_buffer,a
a,ADRL
adrl_buffer,a
START
START
START
:
:
a,status_stack
STATUS,a
a,acc_stack
; disable ADC interrupt
; setup the ACSR register to select f
; setup ADCR register to configure Port PB0~PB3 as A/D inputs
; and select AN0 to be connected to the A/D converter
; reset A/D
; start A/D
; clear ADC interrupt request flag
; enable ADC interrupt
; enable global interrupt
; save ACC to user defined memory
; save STATUS to user defined memory
; read conversion result high byte value from the ADRH register
; save result to user defined register
; read conversion result low byte value from the ADRL register
; save result to user defined register
; reset A/D
; start A/D
; restore STATUS from user defined memory
; restore ACC from user defined memory
; As the Port B channel bits have changed the following START
; signal (0-1-0) must be issued within 10 instruction cycles
A/D Conversion Timing
25
SYS
/8 as the A/D clock
HT46R12A
August 3, 2007