PIC16F870-I/SP View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC16F870-I/SP

28/40-Pin, 8-Bit CMOS FLASH Microcontrollers

Microchip Technology 

PIC16F870/871

10.4 A/D Conversions

Clearing the GO/DONE bit during a conversion will

abort the current conversion. The A/D result register

pair will NOT be updated with the partially completed

A/D conversion sample. That is, the

ADRESH:ADRESL registers will continue to contain

the value of the last completed conversion (or the last

value written to the ADRESH:ADRESL registers).

After the A/D conversion is aborted, a 2TAD wait is

required before the next acquisition is started. After

this 2TAD wait, acquisition on the selected channel is

automatically started.

In Figure 10-3, after the GO bit is set, the first time seg-

mant has a minimum of TCY and a maximum of TAD.

Note: The GO/DONE bit should NOT be set in

the same instruction that turns on the A/D.

FIGURE 10-3: A/D CONVERSION TAD CYCLES

TCY to TAD TAD1 TAD2 TAD3 TAD4 TAD5 TAD6 TAD7 TAD8 TAD9 TAD10 TAD11

b9 b8 b7 b6 b5 b4 b3 b2 b1 b0

Conversion Starts

Holding capacitor is disconnected from analog input (typically 100 ns)

Set GO bit

ADRES is loaded,

GO bit is cleared,

ADIF bit is set,

holding capacitor is connected to analog input.

© 1999 Microchip Technology Inc.

Preliminary

DS30569A-page 85

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