PIC16C782 Microchip Technology Inc., PIC16C782 Datasheet - Page 76

• Manufacturer Part Number: PIC16C782
• Description: 8-bit Cmos Microcontrollers With A/d, D/a, Opamp, Comparators And Psmc
• Manufacturer: Microchip Technology Inc.

PIC16C781/782
FIGURE 9-2:
9.4
Example 9-2 demonstrates an ADC conversion. The
RA0/AN0 pin is configured as the analog input. The ref-
erence voltage selected is the device AV
interrupt is enabled, and the ADC conversion clock is
ADRC.
Clearing the GO/DONE bit during a conversion aborts
the current conversion. The ADRES register is NOT
updated with the partially completed ADC conversion
sample. That is, the ADRES register continues to con-
tain the value of the last completed conversion (or the
last value written to the ADRES register). After the ADC
conversion is aborted, a 2T
before the next acquisition is started. After this 2T
wait period, an acquisition is automatically started on
the selected channel.
DS41171A-page 74
ADC Configuration and
Conversion
Legend: C
VA
ANALOG INPUT MODEL
R
V
I
R
SS
C
S
LEAKAGE
T
PIN
IC
HOLD
AD
ANx
CPIN
5 pF
wait period is required
= input capacitance
= threshold voltage
= leakage current at the pin due to
= interconnect resistance
= sampling switch
= sample/hold capacitance (from DAC)
various junctions
DD
. The ADC
V
DD
V
V
T
T
Preliminary
= 0.6V
= 0.6V
AD
I
± 500 nA
LEAKAGE
EXAMPLE 9-2:
;********************************************
;*
;*
;*
;*
;*
;*
;*
;********************************************
;*
;*
;*
ADC_CNVRT
ADC_CN_LOOP
R
IC
This code block will configure the ADC
Conversion start & wait for complete
for polling, AVDD as reference, RC clock
and RA0 input.
polling code included.
minimum acquisition delay from
configuration.
BANKSEL
CLRF
BSF
BSF
BANKSEL
MOVLW
MOVWF
Start & Wait for ADC complete, assumes
BANKSEL
BSF
BTFSC
GOTO
MOVF
1k
V
SS R
DD
Sampling
Switch
6V
5V
4V
3V
2V
SS
ADCON1
ADCON1
TRISA,0
ANSEL,0
ADCON0
B’11000001’
ADCON0
ADCON0
ADCON0,GO
ADCON0,GO
ADC_CN_LOOP ; If not, wait
ADRES,W
Sampling Switch
5 6 7 8 9 10 11
ADC CONVERSION
V
SS
C
= DAC capacitance
= 51.2 pF
( k
HOLD
2001 Microchip Technology Inc.
)
; Select Bank 1
; AVDD as VREF
; Set RA0 as input
; Set RA0 as analog
; Select Bank0
; RC, Ch 0, ADC on
; Select Bank 0
; Start convert
; Test for end
; Get result