Datasheet

PIC16F785/HV785

12.3 A/D Operation During Sleep

The A/D Converter module can operate during Sleep.

This requires the A/D clock source to be set to the F

option. When the RC clock source is selected, the A/D

waits one instruction before starting the conversion.

This allows the SLEEP instruction to be executed, thus

eliminating much of the switching noise from the con-

version. When the conversion is complete, the GO/

DONE

bit is cleared and the result is loaded into the

ADRESH:ADRESL registers. If the A/D interrupt is

enabled (ADIE and PEIE bits set), the device awakens

from Sleep. If the GIE bit of the INTCON Register is set,

the program counter is set to the interrupt vector

(0004h). If GIE is clear, the next instruction is executed.

If the A/D interrupt is not enabled, the A/D module is

turned off, although the ADON bit remains set.

When the A/D clock source is something other than

RC, a SLEEP instruction causes the present conversion

to be aborted and the A/D module is turned off. The

ADON bit remains set.

FIGURE 12-5: A/D TRANSFER FUNCTION

3FFh

3FEh

A/D Output Code

3FDh

3FCh

004h

003h

002h

001h

000h

Full-Scale

3FBh

1 LSb ideal

Zero-Scale

Transition

REF

Transition

1 LSb ideal

Full-Scale Range

Analog Input Voltage