PIC17LC752-08/JWQTP View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC17LC752-08/JWQTP

High-Performance 8-Bit CMOS EPROM Microcontrollers

Microchip Technology 

PIC17C75X

16.0 ANALOG-TO-DIGITAL

CONVERTER (A/D) MODULE

The analog-to-digital (A/D) converter module has

twelve analog inputs for the PIC17C75X devices.

The A/D allows conversion of an analog input signal to

a corresponding 10-bit digital number. The output of the

sample and hold is the input into the converter, which

generates the result via successive approximation.

The analog reference voltages (positive and negative

supply) are software selectable to either the device’s

supply voltages (AVDD, AVss) or the voltage level on

the RG3/AN0/VREF+ and RG2/AN1/VREF- pins.

The A/D converter has a unique feature of being able

to operate while the device is in SLEEP mode. To oper-

ate in sleep, the A/D clock must be derived from the

A/D’s internal RC oscillator.

The A/D module has four registers. These registers

are:

• A/D Result High Register (ADRESH)

• A/D Result Low Register (ADRESL)

• A/D Control Register0 (ADCON0)

• A/D Control Register1 (ADCON1)

The ADCON0 register, shown in Figure 16-1, controls

the operation of the A/D module. The ADCON1 regis-

ter, shown in Figure 16-2, configures the functions of

the port pins. The port pins can be configured as ana-

log inputs (RG3 and RG2 can also be the voltage refer-

ences) or as digital I/O.

FIGURE 16-1: ADCON0 REGISTER (ADDRESS: 14h, BANK 5)

R/W-0

CHS3

bit7

R/W-0

CHS2

R/W-0

CHS1

R/W-0

CHS0

U-0

R/W-0

U-0

— GO/DONE —

bit 7-4: CHS2:CHS0: Analog Channel Select bits

0000 = channel 0, (AN0)

0001 = channel 1, (AN1)

0010 = channel 2, (AN2)

0011 = channel 3, (AN3)

0100 = channel 4, (AN4)

0101 = channel 5, (AN5)

0110 = channel 6, (AN6)

0111 = channel 7, (AN7)

1000 = channel 8, (AN8)

1001 = channel 9, (AN9)

1010 = channel 10, (AN10)

1011 = channel 11, (AN11)

11xx = RESERVED, do not select

R/W-0

ADON

bit0

R = Readable bit

W = Writable bit

U = Unimplemented bit,

read as ‘0’

- n = Value at POR reset

bit 3: Unimplemented: Read as '0'

bit 2: GO/DONE: A/D Conversion Status bit

If ADON = 1

1 = A/D conversion in progress (setting this bit starts the A/D conversion which is automatically cleared

by hardware when the A/D conversion is complete)

0 = A/D conversion not in progress

bit 1: Unimplemented: Read as '0'

bit 0:

ADON: A/D On bit

1 = A/D converter module is operating

0 = A/D converter module is shutoff and consumes no operating current

© 1997 Microchip Technology Inc.

Preliminary

DS30264A-page 167

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