hd64338023s Renesas Electronics Corporation., hd64338023s Datasheet - Page 273

• Manufacturer Part Number: hd64338023s
• Description: Renesas 8-bit Single-chip Microcomputer Super Low Power Series
• Manufacturer: Renesas Electronics Corporation.

Bit 2—Reserved
This bit is reserved; it can only be written with 0.
Bits 1 and 0—P9 n /PWM Pin Function Switches
These pins select whether pin P9n/PWMn+1 is used as P9n or as PWMn+1.
Bit n
WKPn+1
0
1
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)
Description
Functions as P9
Functions as PWM
n
output pin
n+1
Shutting Down the in the Watch Mode without a Large Current
Flow to Port 9
output pin
PIOFF = 0 (voltage boost circuit on)
PIOFF = 1 (voltage boost circuit off)
PDR9 operation or other operation
Execute SLEEP instruction
Cancel watch mode
Other operation
Watch mode
Rev. 7.00 Mar 10, 2005 page 231 of 652
Section 8 I/O Ports
REJ09B0042-0700
(initial value)
(n = 0 or 1)