20

* This specification are subject to be changed without notice.

8.11.2000

EM73C63

4-BIT MICRO-CONTROLLER FOR LCD PRODUCT

Preliminary

EI

: Enable interrupt Flip-Flop may promit or inhibit all interrupt sources, when inter-

rupt occurs, EI is auto cleared to "0", after RTI instruction is executed, EI is auto

set to "1" again.

Priority checker

: Check interrupt priority when multiple interrupts occur.

INTERRUPT OPERATION

The procedure of interrupt operation:

1. Push PC and all flags to stack.

2. Set interrupt entry address into PC.

3. Set SF= 1.

4. Clear EI to inhibit other interrupts occur.

5. Clear the IL with which interrupt source has already been accepted.

6. Excute interrupt subroutine from the interrupt entry address.

7. CPU accept RTI, restore PC and flags from stack. Set EI to accept other interrupt requests.

PROGRAM EXAMPLE: To enable interrupt of "INT0, TRGA"

LDIA #0100B;

EXAE; set mask register "1100b"

EICIL 010111B ; enable interrupt F.F. and clear IL3 and IL5

LCD DRIVER

It can directly drive the liquid crystal display ( LCD ) and has 40 segments, 16 commons output pins or 8 commons

by music option. There are total 40x16 or 40x8 dots can be display.

(1) LCD driver command register:

Port27 3210

Initial value: 0000

LDC

*

*

LCD DISPLAY CONTROL

LDC

Function description

0

0

LCD display disable

0

1

Blanking

1

0

no function

1

1

LCD display enable

* : Don't care.

P27 is the LCD driver command register. The initial value is 0000.

When LDC ( bit2 and bit3 of P27 ) is set to "00", the LCD display is disabled.

When LDC is set to "01", the LCD is blanking, the COM pins are inactive and the SEG pins

output the display data continuously.

When LDC is set to "11", the LCD display is enabled.

Under stop mode. LDC will be reset to "00".

(2) LCD display data area:

The LCD display data is stored in the display data area of the data memory ( RAM). The LCD display data

area is as illustrated below: