PIC16F526 Datasheet, PDF (61/122 Pages) Microchip Technology – 14-Pin, 8-Bit Flash Microcontroller

PIC16F526
9.1.6
ANALOG CONVERSION RESULT
REGISTER
The ADRES register contains the results of the last
conversion. These results are present during the
sampling period of the next analog conversion process.
After the sampling period is over, ADRES is cleared
(= 0). A ‘leading one’ is then right shifted into the
ADRES to serve as an internal conversion complete
bit. As each bit weight, starting with the MSB, is
converted, the leading one is shifted right and the
converted bit is stuffed into ADRES. After a total of 9
right shifts of the ‘leading one’ have taken place, the
conversion is complete; the ‘leading one’ has been
shifted out and the GO/DONE bit is cleared.
If the GO/DONE bit is cleared in software during a
conversion, the conversion stops. The data in ADRES
is the partial conversion result. This data is valid for the
bit weights that have been converted. The position of
the ‘leading one’ determines the number of bits that
have been converted. The bits that were not converted
before the GO/DONE was cleared are unrecoverable.
REGISTER 9-1: ADCON0: A/D CONTROL REGISTER
R/W-1
ANS1
bit 7
R/W-1
ANS0
R/W-1
ADCS1
R/W-1
ADCS0
R/W-1
CHS1
R/W-1
CHS0
R/W-0
GO/DONE
R/W-0
ADON
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
x = Bit is unknown
bit 7-6
bit 5-4
bit 3-2
bit 1
bit 0
ANS<1:0>: ADC Analog Input Pin Select bits^{(1), (2), (5)}
00 = No pins configured for analog input
01 = AN2 configured as an analog input
10 = AN2 and AN0 configured as analog inputs
11 = AN2, AN1 and AN0 configured as analog inputs
ADCS<1:0>: ADC Conversion Clock Select bits
00 = FOSC/16
01 = FOSC/8
10 = FOSC/4
11 = INTOSC/4
CHS<1:0>: ADC Channel Select bits^{(3, 5)}
00 = Channel AN0
01 = Channel AN1
10 = Channel AN2
11 = 0.6V absolute voltage reference
GO/DONE: ADC Conversion Status bit⁽⁴⁾
1 = ADC conversion in progress. Setting this bit starts an ADC conversion cycle. This bit is automatically cleared
by hardware when the ADC is done converting.
0 = ADC conversion completed/not in progress. Manually clearing this bit while a conversion is in process termi-
nates the current conversion.
ADON: ADC Enable bit
1 = ADC module is operating
0 = ADC module is shut-off and consumes no power
Note 1:
When the ANS bits are set, the channels selected will automatically be forced into Analog mode, regardless of the pin
function previously defined. The only exception to this is the comparator, where the analog input to the comparator and
the ADC will be active at the same time. It is the users responsibility to ensure that the ADC loading on the comparator
input does not affect their application.
2: The ANS<1:0> bits are active regardless of the condition of ADON.
3: CHS<1:0> bits default to 11 after any Reset.
4: If the ADON bit is clear, the GO/DONE bit cannot be set.
5: C1OUT, when enabled, overrides AN2.
 2010 Microchip Technology Inc.
DS41326D-page 61