5

* This specification are subject to be changed without notice.

EM73A89B

4-BIT MICRO-CONTROLLER FOR LCD PRODUCT

8.16.2001

Preliminary

User's program and fixed data are stored in the program ROM. User's program is executed using the PC value

to fetch an instruction code.

The 16Kx8 bits program ROM can be divided into 4 banks. There are 4Kx8 bits per bank.

The program ROM bank is selected by P3(1..0). The program counter is a 13-bit binary counter. The PC and

P3 are initialized to "0" during reset.

When P3(1..0)=00B or 11B, the bank0 and bank1 of program ROM will be selected. P3(1..0)=01B, the bank0

and bank2 will be selected. P3(1..0)=10B, the bank0 and bank3 will be selected.

P3=xx00B

Address

P3=xx11B

P3=xx01B

P3=xx10B

0000h

:

:

Bank0

Bank0

Bank0

0FFFh

1000h

:

:

Bank1

Bank2

Bank3

1FFFh

PROGRAM EXAMPLE:

BANK 0

START:

:

:

:

LDIA #00H

; set program ROM to bank1

OUTA P3

B

XA1

:

XA :

:

:

LDIA #01H

; set program ROM to bank2

OUTA P3

B

XB1

:

XB :

:

:

LDIA #02H

; set program ROM to bank3

OUTA P3

B

XC1

:

XC :

:

:

BXD

XD :

:

:

:

; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

BANK 1

XA1 :

:

:

BXA

:

XA2 :

: