HD6433713 datasheet(233/324 Pages) RENESAS

233 / 324 page

13.2.4 Port Mode Register 0 (PMR0)

PMR0 is an 8-bit write-only register for designating whether each of the port 0 pins is used as a

general-purpose input pin or as an analog input channel to the A/D converter. Designation is

made separately for each pin.

Upon reset, PMR0 is initialized to H'00.

Bit n

ANn

Description

Pin P0n/ANn is used for general-purpose input.

(initial value)

Pin P0n/ANn is an analog input channel.

(n = 0 to 7)

13.3 Operation

The A/D converter operates by successive approximations, and yields its conversion result as 8-bit

data.

A/D conversion begins when software sets the A/D start flag (bit ADSF) to 1. Bit ADSF keeps a

value of 1 during A/D conversion, and is cleared to 0 automatically when conversion is complete.

The completion of conversion also sets bit IRRAD in interrupt request register 3 (IRR3) to 1. An

A/D conversion end interrupt is requested if bit IENAD in interrupt enable register 3 (IENR3) is

set to 1.

If the conversion time or input channel needs to be changed in the A/D mode register (AMR)

during A/D conversion, bit ADSF should first be cleared to 0, stopping the conversion operation,

in order to avoid misoperation.

13.4 Interrupts

When A/D conversion is complete (ADSF changes from 1 to 0), bit IRRAD in interrupt request

A/D conversion end interrupts can be enabled or disabled by means of bit IENAD in interrupt

enable register 3 (IENR3).

For further details see 3.2.2, Interrupts.

Bit

Initial value

Read/Write

AN7

AN6

AN5

AN4

AN3

AN0

AN2

AN1

222

HD6433713 Datasheet(PDF) 233 Page - Renesas Technology Corp