* This specification are subject to be changed without notice.

EM73461B

4-BIT MICRO-CONTROLLER FOR LCD PRODUCT

12.26.2001

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GENERAL DESCRIPTION

EM73461B is an advanced single chip CMOS 4-bit micro-controller. It contains 4K/8K-byte ROM, 244-nibble
RAM, 4-bit ALU, 13-level subroutine nesting, 22-stage time base, two 12-bit timer/counters for the kernel
function. EM73461B also contains 6 interrupt sources, 1 input port, 2 bidirection ports, LCD display (32x4), and
one high speed timer/counter with melody output.
EM73461B has plentiful operating modes (SLOW, IDLE, STOP) intended to reduce the power consumption.

FEATURES

ˇ Operation voltage

: 2.4V to 3.6V.

ˇ Clock source

: Dual clock system. Low-frequency oscillator is Crystal or RC oscillator (32K Hz,

connect an external resistor) by mask option and high-frequency oscillator is RC
oscillator (connect an external resistor), or built-in internal oscillator.

ˇ Instruction set

: 109 powerful instructions for 4K ROM / 107 powerful instructoins for 8K ROM.

ˇ Instruction cycle time : 0.85ľs for 9.2M or 1.7ľs for 4.6M or 2ľs for 4MHz. Selected by mask option (high

speed clock).
122 ľs or 244ľs by frequency double mask option for 32768 Hz (low speed clock).

ˇ ROM capacity

: 4096 X 8 bits / 8192 X 8 bits ROM are choosed by mask option.

ˇ RAM capacity

: 244 X 4 bits.

ˇ Input port

: 1 port (P0). P0(0..3) and IDLE releasing function are available by mask option.

ˇ Bidirection port

: 2 ports (P4, P8). P4.0 and SOUND is available by mask option. P4.1 is shared with

HTC external input. P8(0..3) and IDLE releasing function are available by mask
option.

ˇ 12-bit timer/counter

: Two 12-bit timer/counters are programmable for timer, event counter and pulse width

measurement.

ˇ High speed timer/counter : One 8-bit high speed timer/counters is programmable for auto load timer, melody

output and pulse width measurement.

ˇ Built-in time base counter : 22 stages.
ˇ Subroutine nesting

: Up to 13 levels.

ˇ Interrupt

: External . . . . . 2 input interrupt sources.

Internal . . . . . . 2 Timer overflow interrupts, 1 time base interrupt.

1 high speed timer overflow interrupt.

ˇ LCD driver

: 32 X 4 dots, 1/4duty, 1/3duty, 1/2duty, static, 1/2 bias, 1/3 bias; 6 options selectable.

ˇ Power saving function : SLOW, IDLE, STOP operation mode.
ˇ Package type

: Chip form

61 pins.

APPLICATIONS

EM73461B is suitable for application in family applicance, consumer products, hand held games and the toy
controller.

* This specification are subject to be changed without notice.

EM73461B

4-BIT MICRO-CONTROLLER FOR LCD PRODUCT

12.26.2001

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FUNCTION BLOCK DIAGRAM

Symbol

Pin-type

Function

D D

Power supply (+)

Power supply (-)

RESET

RESET-A

System reset input signal, low active
mask option :

none
pull-up

CLK

OSC-I/OSC-G

RC clock source or capacitor connecting pin for high frequency oscillator

LXIN

OSC-B/OSC-H1 Crystal/RC connecting pin for low speed clock source

LXOUT

OSC-B

Crystal connecting pin for low speed clock source

P0(0..3)/WAKEUP0..3

INPUT-K

4-bit input port with IDLE releasing function
mask option :

wakeup enable, negative edge release, pull-up

wakeup enable, negative edge release, none
wakeup enable, positive edge release, pull-down
wakeup enable, positive edge release, none
wakeup disable, pull-up
wakeup disable, pull-down
wakeup disable, none

P4.0/SOUND

I/O-R

1-bit bidirection I/O port or inverse sound effect output
mask option :

SOUND enable, high current push-pull

SOUND disable, open-drain

PIN DESCRIPTIONS

Interrupt

Control

Time

Base

Timer/Counter

(TA,TB)

System Control

Instruction Decoder

Instruction Register

ROM

Data Bus

Reset

Control

Clock

Generator

Timing

Generator

Sleep Mode

Control

Data pointer

ACC

ALU

Flag

Stack pointer

Stack

ROM

I/O Control

P0.0/WAKEUP0
P0.1/WAKEUP1
P0.2/WAKEUP2
P0.3/WAKEUP3

P4.0/SOUND

P4.1TRGH

P4.2

P4.3

P8.0(INT1)/WAKEUPA

P8.1(TRGB)/WAKEUPB

P8.2(INT0)/WAKEUPC

P8.3(TRGA)/WAKEUPD

RESET

CLK

Clock

Generator

(slow)

LXOUT LXIN

HTC

LCD

V1
V2
V3

COM0~COM3

SOUND

SEG0~SEG31

* This specification are subject to be changed without notice.

EM73461B

4-BIT MICRO-CONTROLLER FOR LCD PRODUCT

12.26.2001

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Symbol

Pin-type

Function

SOUND disable, low current push-pull
SOUND disable, normal current push-pull
SOUND disable, high current push-pull

P4.1/TRGH

I/O-T

1-bit bidirection I/O port with HTC external input
mask option :

NMOS open-drain

PMOS open-drain
low current push-pull
normal current push-pull
high current push-pull

P4(2,3)

I/O-R

2-bit bidirection I/O port with high current source
mask option :

NMOS open-drain

PMOS open-drain
low current push-pull
normal current push-pull
high current push-pull

P8.0(INT1)/WAKEUPA, I/O-S

2-bit bidirection I/O port with external interrupt source input and IDLE

P8.2(INT0)/WAKEUPC

releasing function
mask option :

wakeup enable, low current push-pull

wakeup enable, normal current push-pull
wakeup disable, open-drain
wakeup disable, low current push-pull
wakeup disable, normal current push-pull

P8.1(TRGB)/WAKEUPB I/O-S

2-bit bidirection I/O port with time/counter A,B external input and IDLE

P8.3(TRGA)/WAKEUPD

releasing function
mask option :

wakeup enable, low current push-pull

wakeup enable, normal current push-pull
wakeup disable, open-drain
wakeup disable, low current push-pull
wakeup disable, normal current push-pull

SOUND

Melody output

VA,VB, V1, V2, V3

Connect the capacitors for LCD bias voltage

COM0~COM3

LCD common output pins

SEG0~SEG31

LCD segment output pins

TEST

Tie Vss as package type, no connecting as COB type.

PIN DESCRIPTIONS

FUNCTION DESCRIPTIONS

PROGRAM ROM (4K X 8 bits)

4 K x 8 bits program ROM contains user's program and some fixed data.
The basic structure of program ROM can be divided into 5 parts.
1. Address 000h: Reset start address.
2. Address 002h - 00Ch : 6 kinds of interrupt service routine entry addresses.
3. Address 00Eh-086h : SCALL subroutine entry address, only available at 00Eh,016h,01Eh,026h, 02Eh,

036h, 03Eh, 046h, 04Eh, 056h, 05Eh, 066h, 06Eh, 076h, 07Eh, 086h.

4. Address 000h - 7FFh : LCALL subroutine entry address.
5. Address 000h - FFFh : Except used as above function, the other region can be used as user's program region.

* This specification are subject to be changed without notice.

EM73461B

4-BIT MICRO-CONTROLLER FOR LCD PRODUCT

12.26.2001

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address 4096 x 8 bits
000h

Reset start address

002h

INT0; External interrupt service routine entry address

004h

HTCI; High speed timer interrupt service entry address

006h

TRGA; Timer/counterA interrupt service routine entry address

008h

TRGB; Timer/counter B interrupt service routine entry address

00Ah

TBI; Time base interrupt service routine entry address

00Ch

INT1; External interrupt service routine entry address

00Eh
086h

FFFh

User's program and fixed data are stored in the program ROM. User's program is according the PC value
to send next executed instruction code. Fixed data can be read out by table-look-up instruction.

SCALL, subroutine call entry address

Table-look-up instruction :

Table -look-up instruction is depended on the Data Pointer (DP) to indicate to ROM address, then to get the
ROM code data.

LDAX

Acc

ROM[DP]

LDAXI

Acc

ROM[DP]

,DP+1

DP is a 12-bit data register which can store the program ROM address to be the pointer for the ROM code
data. First, user load ROM address into DP by instruction "STADPL, STADPM, STADPH", then user can
get the lower nibble of ROM code data by instruction "LDAX" and higher nibble by instruction "LDAXI".

PROGRAM EXAMPLE: Read out the ROM code of address 777h by table-look-up instruction.

LDIA #07h;
STADPL

; DP3-0

07h

STADPM

; DP5-4

07h

STADPH

; DP8-6

07h, Load DP=777h

:
LDL #00h;
LDH #03h;
LDAX

; ACC

STAMI

; RAM[30]

LDAXI

; ACC

STAM

; RAM[31]

;
ORG 777h
DATA 56h;
:

* This specification are subject to be changed without notice.

EM73461B

4-BIT MICRO-CONTROLLER FOR LCD PRODUCT

12.26.2001

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PROGRAM ROM (8K X 8 bits)

8 K x 8 bits program ROM contains user's program and some fixed data .
The basic structure of program ROM can be divided into 6 parts.
1. Address 0000h: Reset start address.
2. Address 0002h - 000Ch : 6 kinds of interrupt service routine entry addresses .
3. Address 000Eh - 0086h : SCALL subroutine entry address, only available at 000Eh, 0016h, 001Eh, 0026h, 002Eh,

0036h, 003Eh, 0046h, 004Eh, 0056h, 005Eh, 0066h, 006Eh, 0076h, 007Eh, 0086h.

4. Address 0000h - 07FFh : LCALL subroutine entry address.
5. Address 0000h - 1FFFh : Except used as above function, the other region can be used as user's program region.
6. Address 1000h - 1FFFh : Fixed data stortage area.

address 8192 x 8 bits
000h

Reset start address

002h

INT0; External interrupt service routine entry address

004h

HTCI; High speed timer interrupt service entry address

006h

TRGA; Timer/counterA interrupt service routine entry address

008h

TRGB; Timer/counter B interrupt service routine entry address LCALL entry address

00Ah

TBI; Time base interrupt service routine entry address

00Ch

INT1; External interrupt service routine entry address

00Eh
086h
800h

1000h

FFFh

Bank 1

fixed data area

1FFFh

User's program and fixed data are stored in the program ROM. User's program is according the PC value
to send next executed instruction code. Fixed data can be read out by table-look-up instruction.
Please note that fixed data only can be stored in 8K ROM Bank 1.
The program counter is a 13-bit binary counter. The PC can defined 8K ROM.

SCALL, subroutine call entry address

Part Number EM73461B