13

EM78911

EM78911

EM78911

EM78911

8

88

8-

--

-bit micro

bit micro

bit micro

bit micro-

--

-controller

controller

controller

controller

7. IOCC (LCD DATA)

PAGE0 : Bit7 ~ Bit0 = LCD RAM data register

PAGE1 : 8 bit up-counter (COUNTER2) preset and read out register . ( write = preset)

After a interruption , it

will count from “00”.

8. IOCD (Pull-high Control Register)

PAGE0:

7

6

5

4

3

2

1

0

PH7

PH6

PH5

PH4

PH3

PH2

PH1

PH0

* Bit 0 ~ 7 (/PH#) Control bit used to enable the pull-high of PORT7(#) pin.

1: Enable internal pull-high

0: Disable internal pull-high

PAGE1:

7

6

5

4

3

2

1

0

RO7

RO6

RO5

RO4

RO3

RO2

RO1

RO0

* Bit 7 ~ 0 (RO7~0) Control bit used to enable the R-OPTION of PORT97~PORT90 pin.

1: Enable

0: Disable

RO is used for R-OPTION . Setting RO to ‘1’ will enable the status of R-option pin (P90 ~ P97) to read by

controller. Clearing RO will disable R-option function. If the R-option function is used, user must connect

PORT9 pins to GND by 560K external register . If the register is connected/disconnected , the R9 will

read as “ 0/1” when RO is set to ‘1’.

9. IOCE (Bias,PLL Control Register)

PAGE0 :

7

6

5

4

3

2

1

0

P9SH

P9SL

P6S

Bias3

Bias2

Bias1

0

SC

*

Bit 0 :SC (SCAN KEY signal ) 0/1 = disable/enable. Once you enable this bit , all of the LCD signal will

have a low pulse during a common period. This pulse has 30us width. Please use the procedure to

implement the key scan function.

a.

set port7 as input port

b.

set IOCD page0 port7 pull high

c.

enable scan key signal

d.

Once push a key . Set RA(6)=1 and switch to normal mode.

e.

Blank LCD. Disable scan key signal.

f.

Set P6S =0. Port6 sent probe signal to port7 and read port7. Get the key.

g.

Note!! A probe signal should be delay a instruction at least to another probe signal.

h.

Set P6S =1. Port6 as LCD signal. Enable LCD.