Datasheet
2011-2012 Microchip Technology Inc. DS70652E-page 219
dsPIC33FJ16(GP/MC)101/102 AND dsPIC33FJ32(GP/MC)101/102/104
FIGURE 19-4: ADC CONVERSION CLOCK PERIOD BLOCK DIAGRAM
19.3 ADC Helpful Tips
1. The SMPI<3:0> (AD1CON2<5:2>) control bits:
a) Determine when the ADC interrupt flag is
set and an interrupt is generated if enabled.
b) When the CSCNA bit (AD1CON2<10>) is
set to ‘1’, determine when the ADC analog
scan channel list, defined in the AD1CSSL
register, starts over from the beginning.
2. The ADC has 16 result buffers. ADC conversion
results are stored sequentially in ADC1BUF0-
ADC1BUFF regardless of which analog inputs
are being used, subject to the SMPI<3:0> bits
(AD1CON2<5:2>). There is no relationship
between the ANx input being measured and
which ADC buffer (ADC1BUF0-ADC1BUFF)
that the conversion results will be placed in.
3. The DONE bit (AD1CON1<0>) is only cleared at
the start of each conversion and is set at the
completion of the conversion, but remains set
indefinitely, even through the next sample phase
until the next conversion begins. If application
code is monitoring the DONE bit in any kind of
software loop, the user must consider this
behavior because the CPU code execution is
faster than the ADC. As a result, in Manual
Sample mode, particularly where the user’s
code is setting the SAMP bit (AD1CON1<1>),
the DONE bit should also be cleared by the user
application just before setting the SAMP bit.
19.4 ADC Resources
Many useful resources are provided on the main prod-
uct page of the Microchip web site for the devices listed
in this data sheet. This product page, which can be
accessed using this link, contains the latest updates
and additional information.
19.4.1 KEY RESOURCES
• Section 16. “Analog-to-Digital Converter
(ADC)” (DS70183) in the “dsPIC33F/PIC24H
Family Reference Manual”
• Code Samples
• Application Notes
• Software Libraries
• Webinars
• All related “dsPIC33F/PIC24H Family Reference
Manual” sections
• Development Tools
1
0
ADC Internal
RC Clock
(1)
TOSC
(1)
X2
ADC Conversion
Clock Multiplier
1, 2, 3, 4, 5,..., 64
ADxCON3<15>
TCY
TAD
6
ADxCON3<5:0>
Note 1: See the ADC specifications in Section 26.0 “Electrical Characteristics” for the exact RC clock value.
Note: In the event you are not able to access
the product page using the link above,
enter this URL in your browser: http://
www.microchip.com/wwwproducts/
Devices.aspx?dDocName=en554109