H838024 datasheet(273/697 Pages) RENESAS

273 / 697 page

Section 8 I/O Ports

Rev. 7.00 Mar 10, 2005 page 231 of 652

REJ09B0042-0700

from 1 to 0 only when the PIOFF bit is cleared to 0. Also, if a large current flow is

required, the PIOFF bit should be set to 1 and all the port data bits set to 1. Then clear

PIOFF to 0 and, after allowing 30 clock cycles to permit stabilization of the voltage

boost circuit, clear the port data bits to 0. If time is not provided to allow the voltage

boost circuit to stabilize, it will not be possible to produce a large current flow. There are

no such restrictions when setting port data bits from 0 to 1, regardless of the size of the

current flow. To shut down the voltage boost circuit, set PIOFF to 1 after programming

the port data bits. An example of the sequence of steps is provided below.

(Example Procedure)

Shutting Down the in the Watch Mode without a Large Current

Flow to Port 9

Other operation

PIOFF = 0 (voltage boost circuit on)

PDR9 operation or other operation

PIOFF = 1 (voltage boost circuit off)

Execute SLEEP instruction

Watch mode

Cancel watch mode

Bit 2—Reserved

This bit is reserved; it can only be written with 0.

Bits 1 and 0—P9n/PWM Pin Function Switches

These pins select whether pin P9n/PWMn+1 is used as P9n or as PWMn+1.

Bit n

WKPn+1

Description

Functions as P9n output pin

(initial value)

Functions as PWMn+1 output pin

(n = 0 or 1)

H838024 Datasheet(PDF) 273 Page - Renesas Technology Corp