16F876 Microchip Technology, 16F876 Datasheet - Page 113

• Manufacturer Part Number: 16F876
• Description: 28/40-pin 8-Bit CMOS FLASH Microcontrollers
• Manufacturer: Microchip Technology

The ADRESH:ADRESL registers contain the 10-bit
result of the A/D conversion. When the A/D conversion
is complete, the result is loaded into this A/D result reg-
ister pair, the GO/DONE bit (ADCON0<2>) is cleared
and the A/D interrupt flag bit ADIF is set. The block dia-
gram of the A/D module is shown in Figure 11-1.
After the A/D module has been configured as desired,
the selected channel must be acquired before the con-
version is started. The analog input channels must
have their corresponding TRIS bits selected as inputs.
To determine sample time, see Section 11.1. After this
acquisition time has elapsed, the A/D conversion can
be started. The following steps should be followed for
doing an A/D conversion:
1.
2.
3.
4.
5.
6.
7.
1999 Microchip Technology Inc.
Configure the A/D module:
• Configure analog pins / voltage reference /
• Select A/D input channel (ADCON0)
• Select A/D conversion clock (ADCON0)
• Turn on A/D module (ADCON0)
Configure A/D interrupt (if desired):
• Clear ADIF bit
• Set ADIE bit
• Set GIE bit
Wait the required acquisition time.
Start conversion:
• Set GO/DONE bit (ADCON0)
Wait for A/D conversion to complete, by either:
• Polling for the GO/DONE bit to be cleared
OR
• Waiting for the A/D interrupt
Read
(ADRESH:ADRESL), clear bit ADIF if required.
For next conversion, go to step 1 or step 2 as
required. The A/D conversion time per bit is
defined as T
required before next acquisition starts.
and digital I/O (ADCON1)
A/D
AD
. A minimum wait of 2T
Result
register
AD
pair
is
PIC16F87X
DS30292B-page 113