AD009-041

Page 11 of 14

Version 1.0

DATA_PD

0DH

R/W

xxxx

X

DPD2

DPD1

DPD0

Read Port D data from PD0~PD2 port and

write to PD0~PD2 ( I/O direction is define

by IOC_PD register)

Extended I/O

PDPU

04H

W

0000

X

PDPU.2

PDPU.1

PDPU.0

Port D pull up 150K ohm resistor

0: Port D pull up resistor disabled

1: Port D pull up resistor enabled

PDWK

08H

W

0000

X

PDWK.2 PDWK.1 PDWK.0 Port D wake up enable control

0: Port D wake up disabled

1: Port D wake up enabled

Whether all 3 bits of the Port D is input or output port depends on IOC_PD control register.

Port D also provided edge trigger (rising or falling) wake up and pull up resistor 150K, function just like Port

A or Port B.

6. Wake up func tion for key board scan in halt mode

All Port A, Port B, Port D are provided a special wake up function for hardware keyboard scan in halt mode

automatically.This function can be enabled by option, and individual PIN can be enabled or disabled by

corresponding wake up registers.

It’s built-in one low power RC oscillator 13KHz ± 50% for keyboard scan function operation.

The detail sequence of keyboard scan is described below:

1. Keyboard scan function enabled by KBSCEN option.

2. Set all scan key I/O to input mode.

3. Pull up resistor enabled by PAPU, PBPU or PDPU register.

4. Wake up function enabled by PAWK, PBWK or PDWK register. Keyboard scan function can be

disabled for individual pin by corresponding wake up control registers set to 0.

5. Execute HALT instruction into power down mode.

6. When in halt mode, at the same time only one I/O port direction switch to output state and others are in

input state with pull up resistor. The output port will output one low-pulse from PA2~PA0, PB3~PB0 and

PD2~PD0 sequentially if all wake up registers of all I/O port are enabled. The period of keyboard scan time

is fixed as shown below:

7. In halt mode, MCU will be waked up by rising or falling edge of I/O ports which key scan function is

enabled.

Ta=1. 2 ms±50%, Tb=28ms± 50%

The waveform of keyboard scan function

PD0

PD1

PD2

PB0

PB1

PB2

PB3

PA0

PA1

PA2

PA3(Input)

Pull high

Tb

Ta

PA2 output low

PA2 input with

pull up resistor

PA1 output low

PA1 input with pull

up resistor

Ta