The black diagram now on your screen covers our PIC24F products, at the time of this recording the family consists of nine devices covering memory ranges of 64 K, 96 K and 128 K bytes and 64, 80 and a 100 pin packages. By the time many of you listen to this web seminar there are significantly be more parts. From the point of view in the material in this seminar there will be a very little change as our devices tend to be made with peripherals and compatibility in mind. On the right side of the screen are the peripherals of PIC24F. Today we will cover the peripherals in green and blue beginning with the A/D converter shown in blue. Microchip utilizes a couple of A/D converters in various 16 bay micro controllers and digital signal converters. Today we will cover the 10-bit, 500 K sample per second ADC being used in PIC24F family. The PIC24F embed ADC was selected for PIC24F to provide a high performance ADC that supports a cost effective solution.

Before we take a look at the ADC, please note the red VDI symbol in the corner. The symbol will be used to indicate that the peripherals we are discussing can be configured using visual device initializer or VDI. VDI is found on the tools menu and MP lab IDE as visual initializer. VDI allows a programmer to easily generate initialization code for a peripheral. Now unto the ADC, the ADC in the PIC24F is a 10 bit successive approximation ADC. Design provides high speed conversion and cost effective micro-controller. Some of the features of the ADC are 500 K sample per second conversion speed, upto 16 analog channels. The A/D converter can be referenced to external volt reference pins or analog VDD or analog VSS, the ADC includes automatic channel scan mode. There are selectable conversion trigger sources; there is a 16 word conversion result buffer, the selectable buffer modes and 4 results format options.

The A/D converter can also work during CPU sleep and idle modes, generating an interrupt after the conversions are complete. As mentioned earlier the A/D converter PIC24F single sample can hold 10-bit ADC with 500 K sample per second conversion rate. Upto 16 sample analog pins can be multiplexed into the sample hold circuit. A lower pin count devices not all of the 16 inputs will be implemented. The ADC module contains a 16 result buffer, 16 result buffers can be very useful if you like to make a number of measurements in sleep and then wake up to act upon the measurements.

The buffer can also be splitted in to two 8 result buffers, splitting the buffer into 2 provides the controller time to access half of the result buffers while the other half are being written by the peripheral. The A/D conversion results can be stored in 4 different formats: unsigned integer, signed integer, unsigned fractional or unsigned fractional. This allows the programmer to have the A/D results stored in the format assigned to the variables being used. The reference voltage can be assigned to any accommodations of the external references and to the analog supplies. The A/D allows the users to establish a predefined scan pattern. Finally the conversions can be triggered by a timer compare, a PWM or an external interrupt. In summary the PIC24F is designed for fast, flexible and friendly to low power environment.