Sitronix

ST2024C

PRELIMINARY

24K 8-bit Single Chip Microcontroller

Notice: This is not a final specification. Some parameters are subject to change.

Ver 1.0

8/4/03

8-bit static pipeline CPU
ROM: 24K x 8 bits
RAM: 384 x 8 bits
Operation voltage : 2.4V ~ 3.6V
10 CMOS Bi-directional bit programmable I/O pins
8 Output pins (Shared with LCD common/segment)
Hardware debounce option for input port
Bit programmable PULL-UP for input port
Timer/Counter

- One 8-bit timer / 16-bit event counter
- One 8-bit BASE timer

Five powerful interrupt sources :

- External interrupt (edge trigger)
- TIMER1 interrupt
- BASE timer interrupt
- PORTA[7~0] interrupt (transition trigger)
- DAC reload interrupt

128-level

deep

stack

Dual clock source :

- OSCX: Crystal oscillator: 32.768K Hz
- OSC: RC oscillator 500K ~ 4M Hz

Build-in oscillator with warm-up timer
LCD driver programmable duty :

- 320 ( 8x40) dots ( 1/8 duty, 1/4 bias)
- 160 ( 4x40) dots ( 1/4 duty, 1/3 bias)
- Internal bias resistor(1/4 bias, 1/3 bias) with 32 level

driving strength control.

Programmable Sound Generator (PSG) includes :

- Tone generator
- Sound effect generator
- 4 level volume control
- Digital DAC for speech / tone

Three power down modes :

- WAI0 mode
- WAI1 mode
- STP mode

ST2024C is a low-cost, high-performance, fully static, 8-bit
microcontroller designed with CMOS silicon gate
technology. It comes with 8-bit pipeline CPU core, SRAM,
timer, LCD driver, I/O port, PSG and mask program ROM. A
build-in dual oscillator is specially integrated to enhance

chip performance. For business equipment and consumer
applications. Such as watch, calculator, LCD game and IR
remote control, ST2024C is definitely a perfect solution for
implementation.

ST2024C

Ver 1.0

2/49

8/4/03

CPU

384 x 8

RAM

24K x 8

ROM

40 x 8

LCD RAM

LCD

Driver

Common

Output

Port A

Pull_up A
controller

EXT.

INT

Pull_up B
controller

Port B

DAC INT

PWM DAC

DAC clock

PSG

PSG clock

Reset & Warm_up Timer

Interrupt controller

Base Timer

Timer 1 &

Event counter

Prescaler

PRES

PREW

RC oscillator

32.768K

oscillator

MUX

Segment

Output

Hardware

Debounce

Port A

INT

System controller

Power down controller

PA0

PA1

PA2

PA3

PA4

PA5

PA6

PA7

PB0

PB1

SEG0

SEG1

SEG2

SEG3

COM4

COM5

COM6

COM7

SEG4

SEG39

COM0

COM3

: : :

VDD

Vss

TEST

RESET

OSCI

OSCXO

OSCXI

2 MUX

M
U
X

SYSCK

M
U
X

ST2024C

Ver 1.0

3/49

8/4/03

Designation Pad

# Type

Description

SEG 0 - 3

3~6

LCD Segment output

Output port

SEG 4 - 31

1,2,

36~40,

46~66

LCD Segment output

SEG 32 - 39

28~35

LCD Segment output

COM 0 - 3

24~27

LCD Common output

COM 4 - 7

20~23

LCD Common output

Output port

RESET

Pad reset input (HIGH Active)

VSS

Ground Input and chip substrate

PA0/INTX 19

I/O

Port-A bit programmable I/O

Edge-trigger Interrupt.

Transition-trigger Interrupt

Programmable Timer1 clock source

PA 1-7

12~18

I/O

Port-A bit programmable I/O

Transition-trigger Interrupt

PB 0-1

10, 11

I/O

Port-B bit programmable I/O

PSG/DAC Output

42 P

Power

supply

OSCXI/PB2 8

OSC input pin. For 32768Hz crystal

Port-B input

OSCXO/PB3 7

OSC output pin. For 32768Hz crystal

Port-B input

OSCI

OSC input pin. toward to external resistor

Legend: I = input, O = output, I/O = input/output, P = power.

ST2024C

Ver 1.0

5/49

8/4/03

Unit: �m

PAD CENTER

PAD #

NAME

X Y

1 SEG5 60

2 SEG4

176.600

3 SEG3

286.600

4 SEG2

396.600

5 SEG1

506.600

6 SEG0

616.600

7 OSCX0/PB3

726.600

8 OSCXI/PB2

836.600

9 VSS

946.600

10 PB1

1056.600

11 PB0

1166.600

12 PA7

1276.600

13 PA6

1386.600

14 PA5

1496.600

15 PA4

1606.600

16 PA3

1716.600

17 PA2

1826.600

18 PA1

1942.400

19 PA0/INTX 1942.4

195.500

20 COM7 1942.4

305.500

21 COM6 1942.4

415.500

22 COM5 1942.4

525.500

23 COM4

1942.4

635.500

24 COM3 1942.4

745.500

25 COM2 1942.4

855.500

26 COM1 1942.4

965.500

27 COM0 1942.4

1075.500

28 SEG39 1942.4

1185.500

29 SEG38 1942.4

1295.500

30 SEG37 1942.4

1405.500

31 SEG36 1942.4

1515.500

32 SEG35 1942.4

1625.500

PAD CENTER

PAD #

NAME

X Y

33 SEG34 1942.4

1759.6

34 SEG33

1823.300

1759.6

35 SEG32

1713.300

1759.6

36 SEG31

1603.300

1759.6

37 SEG30

1493.300

1759.6

38 SEG29

1383.300

1759.6

39 SEG28

1273.300

1759.6

40 SEG27

1163.300

1759.6

RESET

1053.300

1759.6

42 VDD

943.300

1759.6

43 OSCI

833.300

1759.6

44 SEG26

723.300

1759.6

45 SEG25

613.300

1759.6

46 SEG24

503.300

1759.6

47 SEG23

393.300

1759.6

48 SEG22

283.300

1759.6

49 SEG21

173.300

1759.6

50 SEG20 60

1759.600

51 SEG19 60

1625.500

52 SEG18 60

1515.500

53 SEG17 60

1405.500

54 SEG16 60

1295.500

55 SEG15 60

1185.500

56 SEG14 60

1075.500

57 SEG13 60

965.500

58 SEG12 60

855.500

59 SEG11 60

745.500

60 SEG10 60

635.500

61 SEG9 60

525.500

62 SEG8 60

415.500

63 SEG7 60

305.500

64 SEG6 60

195.500

ST2024C

Ver 1.0

6/49

8/4/03

PCH PCL

8 7 6 5

1 0 0

Accumulator A

Index Register Y

Index Register X

Program Counter PC

Stack Pointer S

CPU REGISTER MODEL

7.1 Accumulator

(A)

The accumulator is a general purpose 8-bit register which
stores the results of most arithmetic and logic operations. In
addition, the accumulator usually contains one of the two
data words used in these operations.

7.2 Index Registers (X,Y)

There are two 8-bit Index Registers (X and Y) which may be
used to count program steps or to provide and index value to
be used in generating an effective address. When executing
an instruction which specifies indexed addressing, the CPU
fetches the OP code and the base address, and modifies the
address by adding the index register to it prior to performing
the desired operation. Pre or post-indexing of indirect
addresses is possible.

7.3 Stack Pointer (S)

The stack Pointer is an 8-bit register which is used to control
the addressing of the variable-length stack. It's range from
100H to 1FFH total for 256 bytes (128-level deep). The stack
pointer is automatically incremented and decrement under
control of the microprocessor to perform stack

manipulations under direction of either the program or
interrupts (IRQ). The stack allows simple implementation of
nested subroutines and multiple level interrupts. The stack
pointer is initialized by the user's software.

7.4 Program Counter (PC)

The 16-bit Program Counter register provides the address
which step the microprocessor through sequential program
instructions. Each time the microprocessor fetches and
instruction from program memory, the lower byte of the
program counter (PCL) is placed on the low-order bits of the
address bus and the higher byte of the program counter
(PCH) is placed on the high-order 8 bits. The counter is
incremented each time an instruction or data is fetched from
program memory.

7.5 Status Register (P)

The 8-bit Processor Status Register contains seven status
flags. Some of the flags are controlled by the program,
others may be controlled both by the program and the CPU.
The instruction set contains a member of conditional branch
instructions which are designed to allow testing of these
flags.

ST2024C

Ver 1.0

7/49

8/4/03

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

N V 1 B D I Z C

Bit 7: N : Signed flag by arithmetic

1 = Negative
0 = Positive

Bit 6: V : Overflow of signed Arithmetic flag

1 = Negative
0 = Positive

Bit 4: B : BRK interrupt flag *

1 = BRK interrupt occur
0 = Non BRK interrupt occur

Bit 3: D : Decimal mode flag

1 = Decimal mode
0 = Binary mode

Bit 2: I : Interrupt disable flag

1 = Interrupt disable
0 = Interrupt enable

Bit 1: Z : Zero flag

1 = Zero
0 = Non zero

Bit 0: C : Carry flag

1 = Carry
0 = Non carry

* Don't use "BRK" instruction.

TABLE 7-1: STATUS REGISTER (P)

ST2024C

Ver 1.0

8/49

8/4/03

User RAM

0080H
00FFH

128 BYTES

No Use

0040H
007FH

64 BYTES

STACK RAM&

User RAM

0100H
01FFH

256 BYTES

I/O

0000H
003FH

64 BYTES

No Use

0228H
9FFFH

ROM

A000H

FFFFH

24K BYTES

LCD RAM

0200H
0227H

40 BYTES

8.1 ROM

($A000~$FFFF)

The ST2024C has 24K bytes ROM used for program, data and vector address.

Vector address mapping :

$FFFE Reserved.
$FFFC RESET

vector.

$FFFA Reserved.
$FFF8

INTX (PA0) edge interrupter.

$FFF6

Reload DAC data interrupter.

$FFF4 Reserved.
$FFF2 Timer1

interrupter.

$FFF0 PORTA

transition

interrupter.

$FFEE Base

Timer

interrupter.

ST2024C

Ver 1.0

9/49

8/4/03

8.2 RAM

The RAM mapping includes Control Registers, Data RAM, Stack RAM and LCD RAM.

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$000 PA

R/W PA[7] PA[6] PA[5] PA[4] PA[3] PA[2] PA[1] PA[0] 1111

1111

$001 PB

R/W

PB[3]

PB[2]

PB[1]

PB[0]

- - - - - -11

$008 PCA

R/W PCA[7] PCA[6] PCA[5] PCA[4] PCA[3] PCA[2] PCA[1] PCA[0] 0000

0000

$009 PCB

R/W

PCB[1] PCB[0] - - - - - -00

$00F PMCR R/W PULL PDBN INTEG -

PSGO PSGOB 100 - - -00

$010 PSG0L R/W PSG0[7] PSG0[6] PSG0[5] PSG0[4] PSG0[3] PSG0[2] PSG0[1] PSG0[0] 0000 0000
$011 PSG0H R/W

PSG0[11] PSG0[10]

PSG0[9] PSG0[8] - - - - 0000

$012 PSG1L R/W PSG1[7] PSG1[6] PSG1[5] PSG1[4] PSG1[3] PSG1[2] PSG1[1] PSG1[0] 0000 0000
$013 PSG1H R/W

PSG1[11] PSG1[10]

PSG1[9] PSG1[8] - - - - 0000

$014 DAC

R/W DAC[7] DAC[6] DAC[5] DAC[4] DAC[3] DAC[2] DAC[1] DAC[0] 0000

0000

R/W

PCK[2] PCK[1] PCK[0] PRBS C1EN C0EN DACE=0

-000

0000

$016 PSGC

R/W

PCK[2] PCK[1] PCK[0] DMD[1] DMD[0] INH DACE=1

-000

0000

$017 VOL

R/W VOL1[3] VOL1[2] VOL1[1] VOL1[0] VOL0[3] VOL0[2] VOL0[1] VOL0[0] 0000 0000

$020 LCK

R/W

DRV[2] DRV[1] DRV[0] LCK[2] LCK[1] LCK[0] - -00 0100

$021 BTM

R/W

- BTM[3]

BTM[2] BTM[1] BTM[0] - - - - 0000

R PRS[7] PRS[6] PRS[5] PRS[4] PRS[3] PRS[2] PRS[1] PRS[0] 0000

0000

$023 PRS

W SRES SENA SENT

000 - - - - -

$026 T1M

R/W

- T1M[4]

T1M[3]

T1M[2] T1M[1] T1M[0]

- - -0 0000

$027 T1C

R/W T1C[7] T1C[6] T1C[5] T1C[4] T1C[3] T1C[2] T1C[1] T1C[0] 0000

0000

$030 SYS

R/W XSEL OSTP XSTP XBAK WSKP WAIT

0000 00- -

$038 XLCD R/W

- HEAV -

- - - - - -0-

$03A LCTL

W LPWR

BLANK

COMO

LENH SEGO

CTR[1]

CTR[0]

DUTY 0000

0000

$03B SCAN R/W SCAN[7] SCAN[6] SCAN[5] SCAN[4]

0000 - - - -

$03C IREQ R/W

- IRBT

IRPT

IRT1 -

IRDAC

IRX

- - 11 1-11

$03E IENA R/W

- IEBT

IEPT

IET1 -

IEDAC

IEX

- - 00 0-00

Note: 1. Some addresses of I/O area, $2~$7, $A~$E, $15, $18~$1F, $22, $24~$25, $28~$2F, $31~$37, $39,
$3D,$3F, are no used.

2. User should never use undefined addresses and bits.
3. Do not use Bit instructions for write-only registers, such as RMBx, SMBx....
4. E.V.B `s RAM Power On Initial Value are Same as Real Chip.

8.2.2

DATA RAM ($0080~$00FF)

DATA RAM are organized in 256 bytes.

8.2.3

STACK RAM ($0100~$01FF)

STACK RAM are organized in 256 bytes. It provides for a
maximum of 128-level subroutine stacks And can be used
as data memory.

8.2.4 LCD RAM ($0200~$0227)

Resident LCD-RAM, accessible through write and read
instructions, are organized in 40 bytes for 40x8 LCD display.
Note that this area can also be used as data memory.

TABLE 8-2: CONTROL REGISTERS ($0000~$003E)

ST2024C

Ver 1.0

10/49

8/4/03

Name

Name Signal

Signal

Signal Vector

address

Vector address

Priority

Comment

$FFFF,$FFFE

Reserved

RESET External

$FFFD,$FFFC

RESET vector

$FFFB,$FFFA

Reserved

INTX External $FFF9,$FFF8 2

PA0 edge interrupt

DAC Internal $FFF7,$FFF6 3

Reload DAC data interrupt

$FFF5,$FFF4

Reserved

T1 INT/EXT $FFF3,$FFF2 4

Timer1 interrupt

PT External $FFF1,$FFF0 5

Port-A transition interrupt

BT Internal $FFEF,$FFEE 6

Base Timer interrupt

9.2 Interrupt

description

RESET
A positive transition of RESET pin will then cause an
initialization sequence to begin. After the system has been
operating, a high on this line of a least two clock cycles will
cease ST2024C activity. When a positive edge is detected,
there is an initialization sequence lasting six clock cycles.
Then the interrupt mask flag is set, the decimal mode is
cleared and the program counter will loaded with the restart
vector from locations $FFFC (low byte) and $FFFD (high
byte). This is the start location for program control. This input
should be low in normal operation.

INTX interrupt
The IRX (INTX interrupt request) flag will be set while INTX
edge signal occurs. The INTX interrupt will be active once
IEX (INTX interrupt enable) is set, and interrupt mask flag is
cleared. Hardware will push `PC', `P' Register to stack and
set interrupt mask flag (I). Program counter will be loaded
with the INTX vector from locations $FFF8 and $FFF9.

DAC interrupt
The IRDAC (DAC interrupt request) flag will be set while
reload signal of DAC occurs. Then the DAC interrupt will be
executed when IEDAC (DAC interrupt enable) is set, and
interrupt mask flag is cleared. Hardware will push `PC', `P'
Register to stack and set interrupt mask flag (I). Program
counter will be loaded with the DAC vector from locations
$FFF6 and $FFF7.

T1 interrupt
The IRT1 (TIMER1 interrupt request) flag will be set while T1
overflows. With IET1 (TIMER1 interrupt enable) being set,
the T1 interrupt will executed, and interrupt mask flag will be
cleared. Hardware will push `PC', `P' Register to stack and
set interrupt mask flag (I). Program counter will be loaded
with the T1 vector from locations $FFF2 and $FFF3.

PT interrupt
The IRPT (Port-A interrupt request) flag will be set while
Port-A transition signal occurs. With IEPT (PT interrupt
enable)being set, the PT interrupt will be execute, and
interrupt mask flag will be cleared. Hardware will push `PC',
`P' Register to stack and set interrupt mask flag (I). program
counter will be loaded with the PT vector from locations
$FFF0 and $FFF1.

BT interrupt
The IRBT (Base timer interrupt request) flag will be set when
Base Timer overflows. The BT interrupt will be executed
once the IEBT (BT interrupt enable) is set and the interrupt
mask flag is cleared. Hardware will push `PC', `P' Register
to stack and set interrupt mask flag (I). Program counter will
be loaded with the BT vector from locations $FFEE and
$FFEF.

TABLE 9-3: PREDEFINED VECTORS FOR INTERRUPT

ST2024C

Ver 1.0

11/49

8/4/03

9.3 Interrupt

request

clear

Interrupt request flag can be cleared by two methods. One is
to write "0" to IENA, the other is to initiate the interrupt

service routine when interrupt occurs. Hardware will
automatically clear the Interrupt flag.

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$03C IREQ R/W

- IRBT

IRPT

IRT1 -

IRDAC

IRX

- - 11 1-11

Bit 5: IRBT: Base Timer Interrupt Request bit
1 = Time base interrupt occurs

0 = Time base interrupt doesn't occur

Bit 4: IRPT: Port-A Interrupt Request bit
1 = Port-A transition interrupt occurs

0 = Port-A transition interrupt doesn't occur

Bit 3: IRT1: Timer1 Interrupt Request bit
1 = Timer1 overflow interrupt occurs

0 = Timer1 overflow interrupt doesn't occur

Bit 1: IRDAC: DAC reload Interrupt Request bit
1 = DAC time out interrupt occurs

0 = DAC time out interrupt doesn't occur

Bit 0: IRX: INTX Interrupt Request bit
1 = INTX edge interrupt occurs

0 = INTX edge interrupt doesn't occur

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$03E IENA R/W

- IEBT

IEPT

IET1 -

IEDAC

IEX

- - 00 0-00

Bit 5: IEBT: Base Timer Interrupt Enable bit
1 = Time base interrupt enable

0 = Time base interrupt disable

Bit 4: IEPT: Port-A Interrupt Enable bit
1 = Port-A transition interrupt enable

0 = Port-A transition interrupt disable

Bit 3: IET1: Timer1 Interrupt Enable bit
1 = Timer1 overflow interrupt enable

0 = Timer1 overflow interrupt disable

Bit 1: IEDAC: DAC reload Interrupt Enable bit
1 = DAC time out interrupt enable

0 = DAC time out interrupt disable

Bit 0: IEX: INTX Interrupt Enable bit
1 = INTX edge interrupt enable

0 = INTX edge interrupt disable

TABLE 9-4: INTERRUPT REQUEST REGISTER (IREQ)

TABLE 9-5: INTERRUPT ENABLE REGISTER (IENA)

ST2024C

Ver 1.0

12/49

8/4/03

ST2024C has four I/O ports, PORT-A, PORT-B,
SEGMENT-PORT and COMMON-PORT. In total, ST2024C
provides for a maximum of 18 I/O pins with both

SEGMENT-PORT and COMMON-PORT being programmed
as output ports. For detail pin assignment, please refer to
Table 9-6 :

PORT NAME

PAD NAME

PAD

NUMBER

PIN

TYPE

FEATURE

PA0/INTX 18 I/O

PA1 17

I/O

PA2 16

I/O

PA3 15

I/O

PA4 14

I/O

PA5 13

I/O

PA6 12

I/O

PORTA

PA7 11

I/O

Programmable input/output pin

PB0 10

I/O

PB1

I/O

Programmable input/output pin

PB2 43

PORTB

PB3 44

Input pin(Mask Option)

SEG0 6

SEG1 5

SEG2 4

SEGMENT

PORT

SEG3 3

These 4 segment pins can be programmed as
output ports.

COM4 22

COM5 21

COM6 20

COMMON

PORT

COM7 19

These 4 common pins can be programmed as output
ports.

TABLE 10-6: I/O DESCRIPTION

ST2024C

Ver 1.0

13/49

8/4/03

10.2 PORT-A

Port- A is a bit-programmable bi-direction I/O port, which is
controlled by PCA register. It provides user with bit

programmable pull-up MOS, interrupt debounce and
interrupt edge selection(PA0 only).

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$000 PA

R/W PA[7] PA[6] PA[5] PA[4] PA[3] PA[2] PA[1] PA[0] 1111

1111

$008 PCA R/W PCA[7] PCA[6] PCA[5] PCA[4] PCA[3] PCA[2] PCA[1] PCA[0] 0000

0000

$00F PMCR R/W PULL PDBN

INTEG -

PSG0

PSGB

100 - - -00

$03C IREQ R/W

IRBT IRPT IRT1

IRDAC

IRX

- - 11 1-11

$03E IENA R/W

IEBT IEPT IET1

IEDAC

IEX

- - 00 0-00

10.2.2 PORT-A

I/O

control

Direction of Port-A is controlled by PCA. Every bit of
PCA[7~0] is mapped to the I/O direction of PA[7~0]

correspondingly, with "1" for output mode, and "0" for input
mode.

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$008 PCA R/W PCA[7] PCA[6] PCA[5] PCA[4] PCA[3] PCA[2] PCA[1] PCA[0] 0000

0000

Bit 7~0: PCA[7~0] : Port-A directional bits

1 = Output mode
0 = Input mode

TABLE 10-7: SUMMARY FOR PORT-A REGISTERS

TABLE 10-8: PORT-A CONTROL REGISTER (PCA)

ST2024C

Ver 1.0

14/49

8/4/03

10.2.3 PORT-A PULL-UP

OPTION

PORT-A contains pull-up MOS transistors controlled by
software. When an I/O is used as an input. The ON/OFF of
the pull-up MOS transistor will be controlled by port data
register (PA) and the pull-up MOS will be enabled with "1"

for data bit and disable with "0" for data bit. The PULL
control bit of PMCR controls the ON/OFF of all the pull-up
MOS simultaneously. Please refer to the Figure 9-1.

FIGURE 10-1: Port-A Configuration Function Block Diagram

VCC

PORT
DATA
REGISTER
( PDR )

PULL-UP

PMOS

PULL-UP

RD_INPUT

DATA INPUT

PORT
CONTROL
REGISTER
( PCR )

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$00F PMCR R/W PULL PDBN

INTEG -

PSG0

PSGB

100 - - -00

Bit 7: PULL : Enable all pull-up function bit

1 = Enable pull-up function
0 = Disable pull-up function

Bit 6: PDBN : Enable Port-A interrupt debounce bit

1 = Debounce for Port-A interrupt
0 = No debounce for Port-A interrupt

Bit 5: INTEG : INTX interrupt edge select bit

1 = Rising edge
0 = Falling edge

TABLE 10-9: PORT CONDITION CONTROL REGISTER (PMCR)

ST2024C

Ver 1.0

15/49

8/4/03

10.2.4 Port-A interrupt

Port-A, a programmable I/O, can be used as a port interrupt
when it is in the input mode. Any edge transition of the
Port-A input pin will generate an interrupt request. The last
state of Port-A must be kept before I/O transition and this
can be accomplished by reading Port-A.

When programmer enables INTX and PT interrupts, PA0
trigger occur. INTX and PT interrupts will therefore happen
sequentially. Please refer to the Figure 9-2.

Operating Port-A interrupt step by step :

1. Set input mode.
2. Read Port-A.
3. Clear interrupt request flag (IRPT).
4. Set interrupt enable flag (IEPT).
5. Clear CPU interrupt disable flag (I).
6. Read Port-A before `RTI' instruction in

INT-Subroutine.

Example :

.
.
.

STZ

PCA

;Set input mode.

LDA #$FF
STA

;PA be PULL-UP.

LDA

;Keep last state.

RMB4 <IREQ

;Clear

IRQ

flag.

SMB4 <IENA

;Enable

INT.

CLI

.
.

INT-SUBROUTINE

.
.

LDA

;Keep last state.

RTI

FIGURE 10-2: Port Interrupt Logic Diagram

NAND8

OR2

DFF

XNOR2

RDPA

PA[0]

PA[4]

PCA[0]

PCA[4]

PA[1]

PA[5]

PCA[1]

PCA[5]

PA[2]

PA[6]

PCA[2]

PCA[6]

PA[3]

PA[7]

PCA[3]

PCA[7]

PTIR

High Level Interrupt

ST2024C

Ver 1.0

16/49

8/4/03

10.2.4.2

Port-A interrupt debounce

ST2024C has hardware debounce option for Port-A
interrupt. The debounce will be enabled with "1" and disable
with "0" for PDBN. The debounce will active when Port-A
transition occurs, PDBN enable and OSCX enable.

The debounce time is OSCX x 512 cycles(about 16 ms).
Refer to the TABLE 9-10.

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$00F PMCR R/W

PULL PDBN INTEG

PSG0

PSGB

100 - - -00

Bit 6: PDBN : Enable Port-A interrupt debounce bit

1 = Debounce for Port-A interrupt
0 = No debounce for Port-A interrupt

TABLE 10-10: PORT CONDITION CONTROL REGISTER (PMCR)

ST2024C

Ver 1.0

17/49

8/4/03

10.2.5 PA0/INTX

PA0 can be used as an external interrupt input(INTX).
Falling or Rising edge is controlled by INTEG(PMCR[5]) and
the external interrupt is set up with "0" for falling edge and "1"
for rising edge. Please refer to the Figure 9-3.

When programmer enables INTX and PT interrupts, PA0
trigger will occur. Both INTX and PT interrupts will happen
sequentially. Pelase refer to the operating steps.

Operating INTX interrupt step by step :

Set PA0 pin into input mode. (PCA[0])

Select edge level. (INTEG)

Clear INTX interrupt request flag. (IRX)

Set INTX interrupt enable bits. (IEX)

Clear CPU interrupt mask flag (I).

Example :

.
.
.

RMB0 <PCA

;Set

input

mode.

SMB5 <PMCR

;Rising

edge.

RMB0 <IREQ

;Clear

IRQ

flag.

SMB0 <IENA

;Enable

INTX

interrupt.

CLI

.
.
.

FIGURE 10-3: INTX Logic Diagram

PMCR[5]

PA 0/INTX

Falling Edge Interrupt

ST2024C

Ver 1.0

18/49

8/4/03

10.3 PORT-B

Port -B is a bit programmable bi-direction I/O port, which is
controlled by PCB register. It also provides user with bit-

programmable pull-up MOS and sound output port
separately.

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$001 PB

R/W

PB[3]*

PB[2]*

PB[1]

PB[0]

- - - - - -11

$009 PCB R/W

PCB[1] PCB[0] - - - - - -00

$00F PMCR R/W PULL PDBN

INTEG

PSG0

PSGB

100 - - -00

Note:because PB2,PB3 is input pin,so PB[2],PB[3] only read status.

10.3.2 PORT-B

I/O

control

Direction of Port-B is controlled by PCB. Every bit of
PCB[1~0] is mapped into the I/O direction of PB[1~0]

correspondingly, with "1" for output mode, and "0" for input
mode.

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$009 PCB R/W

PCB[1] PCB[0] - - - - - -00

Bit 1~0: PCB[1~0] : Port-B directional bits

1 = Output mode
0 = Input mode

TABLE 10-11: SUMMARY FOR PORT-B REGISTERS

TABLE 10-12: PORT-B CONTROL REGISTER (PCB)

ST2024C

Ver 1.0

19/49

8/4/03

10.3.3 PORT-B PULL-UP

OPTION

This port contains pull-up MOS transistors which is
controlled by software and can be enabled or disabled with
"1" or with "0" accordingly in data bit of the port data register

(PB) when an I/O is used as an input. The PULL control bit
of PMCR also controls the ON/OFF of all pull-up MOS
simultaneously. Please refer to the Figure 9-4.

FIGURE 10-4: Port-B Configuration Function Block Diagram

VCC

PORT
DATA
REGISTER
( PDR )

PULL-UP

PMOS

PULL-UP

RD_INPUT

DATA INPUT

PORT
CONTROL
REGISTER
( PCR )

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$00F PMCR R/W PULL PDBN

INTEG

PSGO PSGOB 100 - - -00

Bit 7: PULL : Enable all pull-up functions bit

1 = Enable pull-up function
0 = Disable pull-up function

Bit 1: PSGO : PSG output enable bit

1 = PB1 is PSG data output pin if PB1 is set in output mode
0 = PB1 is normal I/O pin

Bit 0: PSGOB : PSG inverse signal output enable bit

1 = PB0 is PSG inverse data output pin if PB0 is set in output mode
0 = PB0 is normal I/O pin

TABLE 10-13: PORT CONDITION CONTROL REGISTER (PMCR)

ST2024C

Ver 1.0

20/49

8/4/03

10.4 SEGMENT-PORT

The SEG0~SEG3 can be used as LCD drivers or output
ports. In output port mode, programmer must write
$FF($00) into LCD RAM in order to output FLOAT(LOW).

The assignments of SEGO will be decided by Bit 3 of
LCTL[3]. Please refer to TABLE9-14.

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$03A LCTL W

LPWR BLANK COMO

LENH SEGO CTR[1] CTR[0]

DUTY

0000 0000

Bit 3: SEGO : Segment output selection bit

1 = SEG0-SEG3 used as output pins
0 = SEG0-SEG3 used as LCD segment pins

Address

Name

R/W Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$200

SEGMENT OUT 0 W

SEGMENT-0 OUTPUT BIT

???? ????

$201

SEGMENT OUT 1 W

SEGMENT-1 OUTPUT BIT

???? ????

$202

SEGMENT OUT 2 W

SEGMENT-2 OUTPUT BIT

???? ????

$203

SEGMENT OUT 3 W

SEGMENT-3 OUTPUT BIT

???? ????

In the output port mode, programmer must write $FF($00) into LCD RAM to output FLOAT(LOW).

TABLE 10-14: LCD CONTROL REGISTER (LCTL)

TABLE 10-15: SEGMENT OUT REGISTER

ST2024C

Ver 1.0

21/49

8/4/03

10.5 COMMON-PORT

The COM4~COM7 can be used as LCD drivers or output
ports. In output port mode, SCAN[7~4] will be map to
COM7~COM4 output ports, which pin assignment will be

decided by Bit 5 of LCTL[5], Please refer to the following
table.

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$03A LCTL W

LPWR BLANK COMO LENH

SEGO

DUTY

0000 0- -0

Bit 5: COMO : Common output selection bit

1 = COM4~COM7 used as output pins
0 = COM4~COM7 used as LCD Common pins

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$03B SCAN R/W SCAN[7] SCAN[6] SCAN[5] SCAN[4]

0000 - - - -

Bit 4: SCAN[4] : COM4 scan output bit

1 = COM4 output =FLOAT
0 = COM4 output =LOW

Bit 5: SCAN[5] : COM5 scan output bit

1 = COM5 output = FLOAT
0 = COM5 output =LOW

Bit 6: SCAN[6] : COM6 scan output bit

1 = COM6 output = FLOAT
0 = COM6 output =LOW

Bit 7: SCAN[7] : COM7 scan output bit

1 = COM7 output = FLOAT
0 = COM7 output =LOW

TABLE 10-16: LCD CONTROL REGISTER (LCTL)

TABLE 10-17: SCAN OUTPUT REGISTER (SCAN)

ST2024C

Ver 1.0

22/49

8/4/03

ST2024C is with dual-clock system. Programmer can
choose between OSC(RC) and OSCX(32.768k), or both as
clock source through program. The system clock(SYSCK)
also can be switched between OSC and OSCX. The OSC
will be switch with "0" and OSCX will be switch with "1" for

XSEL. Whenever system clock be switch, the warm-up
cycles are occur at the same time. That is confirm SYSCK
really switched when read XSEL bit. LCD driver, Timer1,
Base Timer and PSG can utilize these two clock sources as
well.

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$030 SYS R/W XSEL OSTP XSTP XBAK WSKP WAIT

0000 00- -

Bit 7: XSEL : System clock select(write) / confirm(read) bit

1 = OSCX
0 = OSC

Bit 6: OSTP : OSC stop control bit

1 = Disable OSC
0 = Enable OSC

Bit 5: XSTP : OSCX stop control bit

1 = Disable OSCX
0 = Enable OSCX

Bit 4: XBAK : OSCX driver heavy load bit

1 = OSCX normal load
0 = OSCX heavy load

Bit 3: WSKP : System warm-up control bit

1 = Warm-up to 16 oscillation cycles
0 = Warm-up to 256 oscillation cycles

Bit 2: WAIT : WAI-0 / WAI-1mode select bit (Refer to POWER DOWN MODE)

1 = WAI instruction causes the chip to enter WAI-1 mode
0 = WAI instruction causes the chip to enter WAI-0 mode

Note:
1. The XSEL(SYS[7]) bit will show which real working mode is when it is read.

FIGURE 11-5: System Clock Diagram

OUT

MUX2

IN0

IN1

OUTPUT

SEL

OSC

SYSCK

OSCX

XSEL

Frequency divided by 2

TABLE 11-18: SYSTEM CONTROL REGISTER (SYS)

ST2024C

Ver 1.0

23/49

8/4/03

The ST2024C has two timers: Base timer/Timer1, and two
prescalers (PRES and PREW). There are two clock sources

for PRES and one clock source(OSCX) for PREW. Please
refer to the following table:

SENT Clock

source(TCLK) MODE

1 INTX

Event

counter

0 SYSCK Timer

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$021 BTM R/W

- BTM[3]

BTM[2] BTM[1] BTM[0] - - - - 0000

PRS[7] PRS[6] PRS[5] PRS[4] PRS[3] PRS[2] PRS[1] PRS[0] 0000

0000

$023 PRS

W SRES SENA SENT

000 - - - - -

$026 T1M R/W

- T1M[4]

T1M[3]

T1M[2] T1M[1] T1M[0]

- - -0 0000

$027 T1C

R/W T1C[7] T1C[6] T1C[5] T1C[4] T1C[3] T1C[2] T1C[1] T1C[0] 0000

0000

$030 SYS R/W XSEL OSTP XSTP XBAK

WSKP WAIT

0000 00- -

$03C IREQ R/W

- IRBT

IRPT IRT1 -

IRDAC

IRX

- - 11 1-11

$03E IENA R/W

- IEBT

IEPT IET1 -

IEDAC

IEX

- - 00 0-00

SYSCK

INTX

SENT

SEL

MUX

SRES-PULSE

SENA

ENABLE

CLEAR

OUTPUT

TCLK

PREW

OUTPUT

OSCX/256

OSCX/64

OSCX/16

OSCX/4

RESET

OSCX

RESET

IN0

IN1

TCLK/256

TCLK/32

TCLK/8
TCLK/2

PRES

BASE TIMER

TIMER 1

OSCX/128

OSCX/32

FIGURE 12-6: Prescaler for Timers

TABLE 12-19: CLOCK SOURCE (TCLK) FOR PRES

TABLE 12-20: SUMMARY FOR TIMER REGISTERS

ST2024C

Ver 1.0

24/49

8/4/03

12.2 PRES

The prescaler PRES is an 8-bits counter as shown in Figure
11-6. Which provides four clock sources for base timer and
timer1, and it is controlled by register PRS. The instruction
read toward PRS will bring out the content of PRES and the

instruction write toward PRS will reset, enable or select clock
sources for PRES.
When user set external interrupt as the input of PRES for
event counter, combining PRES and Timer1 will get a
16bit-event counter.

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

PRS[7] PRS[6] PRS[5] PRS[4] PRS[3] PRS[2] PRS[1] PRS[0] 0000

0000

$023 PRS

W SRES SENA SENT

000 - - - - -

READ

Bit 7~0: PRS[7~0] : 1's complement of PRES counter

WRITE

Bit 7: SRES : Prescaler Reset bit

Write "1" to reset the prescaler (PRS[7~0])

Bit 6: SENA : Prescaler enable bit

0 = Disable prescaler counting
1 = Enable prescaler counting

Bit 5: SENT : Clock source(TCLK) selection for prescaller PRES

0 = Clock source from system clock "SYSCK"
1 = Clock source from external events "INTX"

12.3 PREW

The prescaler PREW is an 8-bits counter as shown in Figure
11-6. PREW provides four clock source for base timer and

timer1. It stops counting only if OSCX stops or hardware
reset occurs.

TABLE 12-21: PRESCALER CONTROL REGISTER (PRS)

ST2024C

Ver 1.0

25/49

8/4/03

12.4 Base timer

Base timer is an 8-bit up counting timer. When it overflows
from $FF to $00, a timer interrupt request IRBT will be
generated. Please refer to Figure 11-7. :

FIGURE 12-7: Structure of Base Timer

IN0

IN1

IN2

IN3

SEL

PRES

BTM[1~0]

MUX4-1

PREW

IN0

IN1

IN2

IN3

SEL

BTM[1~0]

BTM[3]

IN0

IN1

SEL

MUX

8 Bit - UP Counter

CLOCK

IRBT

MUX 4-1

OSCX/256

OSCX/64

OSCX/16

OSCX/4

TCLK/256

TCLK/32

TCLK/8

TCLK/2

OUT

12.4.2 Clock source control for Base Timer

Several clock sources can be selected for Base Timer.
Please refer to the following table:

* SENA

BTM[3]

BTM[2] BTM[1] BTM[0] Base

Timer

source

clock

0 0 X

X STOP

1 0 X 0 0

TCLK

256

1 0 X

TCLK / 32

1 0 X 1 0

TCLK

1 0 X

TCLK / 2

X 1 X

OSCX / 256

X 1 X

OSCX / 64

X 1 X

OSCX / 16

X 1 X

OSCX / 4

* TCLK will stop when an `0' is written to SENA(PRS[6]).

TABLE 12-22: CLOCK SOURCE FOR BASE TIMER

ST2024C

Ver 1.0

26/49

8/4/03

12.5 Timer 1

The Timer1 is an 8-bit up counter. It can be used as a timer
or an event counter. T1C($27) is a real time read/write
counter. When an overflow from $FF to $00, a timer interrupt
request IRT1 will be generated. Timer1 will stop counting
when system clock stops. Please refer to Figure 11-8.

FIGURE 12-8: Timer1 Structure Diagram

IN0

IN1

IN2

IN3

SEL

PRES

T1M[1~0]

MUX4-1

PREW

IN0

IN1

IN2

IN3

SEL

T1M[1~0]

MUX

8 Bit - UP Counter

CLOCK

IRT1

MUX 4-1

OSCX/256

OSCX/128

OSCX/64

OSCX/32

TCLK/256

TCLK/32

TCLK/8

TCLK/2

OUT

IN0

IN1

OUT

SEL

D Flip-Flop

SYSCK

MUX

T1M[3]

Auto Reload

T1M[4]

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$027 T1C R/W T1C[7] T1C[6] T1C[5] T1C[4] T1C[3] T1C[2] T1C[1] T1C[0] 0000

0000

12.5.1.2

Bit 7-0: T1C[7-0] : Timer1 up counter register

TABLE 12-23: TIMER1 COUNTING REGISTER (T1C)

ST2024C

Ver 1.0

27/49

8/4/03

12.5.2 Clock source control for Timer1

Several clock source can be chosen from for Timer1. It's
very important that Timer1 can keep counting as long as
SYSCK stays active. Refer to the following table:

* SENA

T1M[4]

T1M[3]

T1M[2] T1M[1] T1M[0] Clock

source

Auto-Reload

X 0 X

X STOP

1 0 0 X 0 0

TCLK

256 No

1 0 0 X 0 1

TCLK

32 No

1 0 0 X 1 0

TCLK

8 No

1 0 0 X 1 1

TCLK

2 No

X 0 1 X

OSCX / 256

X 0 1 X

OSCX / 128

X 0 1 X

OSCX / 64

X 0 1 X

OSCX / 32

1 1 0 X 0 0

TCLK

256

Yes

1 1 0 X 0 1

TCLK

32 Yes

1 1 0 X 1 0

TCLK

8 Yes

1 1 0 X 1 1

TCLK

2 Yes

X 1 1 X

OSCX / 256

Yes

X 1 1 X

OSCX / 128

Yes

X 1 1 X

OSCX / 64

Yes

X 1 1 X

OSCX / 32

Yes

* TCLK would stop when SENA is set to 0.

TABLE 12-24: CLOCK SOURCE FOR TIMER1

ST2024C

Ver 1.0

28/49

8/4/03

The built-in dual channel Programmable Sound Generator
(PSG) is controlled by registers directly. Its flexibility through
setting several parameters to registers makes it useful in
many applications, such as music synthesis, sound effects
generation, audible alarms and tone generation. PSG will
finish the reset when user needs to create sound effect. The

structure of PSG is shown in Figure 12-10 and its clock
sources are shown in Figure 12-9. The ST2024C has three
PSG playing type.one for channel0(C0) & channel1(C1)
square type sound playing.One for ch0 square tone sound
and ch1 noise sound.The third sound playing type is DAC
PCM playing.

FIGURE 13-9: Clock Source for PSG

SYSCK

OSCX

PSGC[6~4]

IN0

IN1

Output

Select

PSG Selector

PSGCK

PSGC

SYSCK/2

PSGCK

SYSCK/4

SYSCK/8

SYSCK/16

SYSCK

OSCX

B6 B5 B4

X
X

0
1
1

0
1

FIGURE 13-10: Program Sound Generator

Enable Output

Enable

LOAD

Output

MUX2

IN0

IN1

OUTPUT

SEL

MUX2

IN0

IN1

OUTPUT

SEL

MUX2

IN0

IN1

OUTPUT

SEL

MIXER

CH1

Output

Vol_CH1

DACE

C1TEN

C1Tone

C1out

DACE
PSGC[2]

C1NEN

C1Noise

PSGC[3]

PSGOUT

C1out

VOL1[3~0]

PSGOUTB

BDB

DACE

To Port B

From DAC Generator

Channel 1 Tone

Channel 1 Noise

Preload Data Before First Count

ST2024C

Ver 1.0

29/49

8/4/03

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$00F PMCR R/W

PULL

PDBN

INTEG

PSGO

PSGB

100 - - -00

$010 PSG0L R/W PSG0[7] PSG0[6] PSG0[5] PSG0[4] PSG0[3] PSG0[2] PSG0[1] PSG0[0] 0000 0000

$11 PSG0H R/W

PSG0[11] PSG0[10]

PSG0[9] PSG0[8] - - - - 0000

$012 PSG1L R/W PSG1[7] PSG1[6] PSG1[5] PSG1[4] PSG1[3] PSG1[2] PSG1[1] PSG1[0] 0000 0000
$013 PSG1H R/W

PSG1[11] PSG1[10]

PSG1[9] PSG1[8] - - - - 0000

R/W

PCK[2] PCK[1] PCK[0] PRBS C1EN C0EN DACE=0

000

0000

$016 PSGC

R/W

PCK[2] PCK[1] PCK[0] DMD[1] DMD[0]

INH

DACE=1 - 000 0000

$017 VOL

R/W VOL1[3] VOL1[2] VOL1[1] VOL1[0] VOL0[3] VOL0[2] VOL0[1] VOL0[0] 0000 0000

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$00F PMCR R/W

PULL

PDBN

INTEG

PSGO

PSGB

100 - - -00

Bit 1: PSGO : PSG output enable bit

1 = PSG data output pin if PB1 is set in output mode
0 = PB1 is normal I/O pin

Bit 0: PSGB : PSG inverse signal output enable bit

1 = PB0 is PSG inverse data output pin if PB0 is set in output mode
0 = PB0 is normal I/O pin

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$017 VOL R/W VOL1[3]

VOL1[2]

VOL1[1] VOL1[0] VOL0[3] VOL0[2] VOL0[1] VOL0[0] 0000

0000

Bit 3~0: VOL0[3~0] : PSG volume control bit

0000 = No sound output

0001 = 1/16 volume (PSGCK must >= 320K Hz)
0010 = 2/16 volume
:
1110 = 15/16 volume
1111 = Maximum volume (PSGCK must >= 20K Hz)

Bit 7~4: VOL1[3~0] : PSG volume control bit

0000 = No sound output

0001 = 1/16 volume (PSGCK must >= 320K Hz)
0010 = 2/16 volume
:
1110 = 15/16 volume

1111 = Maximum volume (PSGCK must >= 20K Hz)

Only use Channel-0 and VOL=0FFHvolume is maximum.

TABLE 13-25: SUMMARY FOR PSG REGISTERS

TABLE 13-26: CONTROL REGISTER FOR PSG OUTPUT (PMCR)

TABLE 13-27: CONTROL REGISTER FOR PSG VOLUME (VOL)

ST2024C

Ver 1.0

30/49

8/4/03

13.2 Tone Generator

The tone frequency is decided by PSGCK and 12-bit
programmable divider (PSG0[11~0]) and (PSG1[11~0])
Please refert Figure12-11.

FIGURE 13-11: Channel0 PSG Tone Counter

12 Bit Auto-reload Up Counter

Tone out

OUTPUT

PSG0[11~8]

PSG0[7~0]

LOAD

C0EN

PSGCK

C0[11~8]

C0[7~0]

Latch

Enable

Frequency of Channel 0 Tone = PSGCK/(1000H-PSG0[11~0])/2

CLOCK

Channel 0

FIGURE 13-12: Channel1 PSG Tone Counter

12 Bit Auto-reload Up Counter

Tone out

OUTPUT

PSG1[11~8]

PSG1[7~0]

LOAD

C1EN

PSGCK

C1[11~8]

C1[7~0]

Latch

Enable

Frequency of Channel 1 Tone = PSGCK/(1000H-PSG1[11~0])/2

CLOCK

Channel 1

ST2024C

Ver 1.0

31/49

8/4/03

13.3 PSG Tone programming

To program tone generator, PSGO (PMCR[1]) or PSGB
(PMCR[ 0]) should be set to "1" for PB1 or PB0 in order to be
in the PSG output mode. Tone or DAC function is defined by
DACE, writing to C1EN will enable tone generator when

PSG is in tone function. Noise or tone function is selected by
PRBS.

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

R/W

PCK[2] PCK[1] PCK[0] PRBS C1EN C0EN DACE=0

000

0000

$016 PSGC

R/W

PCK[2] PCK[1] PCK[0] DMD[1] DMD[0]

INH

DACE=1 - 000 0000

Bit 0: DACE : Tone(Noise) or DAC Generator selection bit

1 = PSG is used as the DAC generator
0 = PSG is used as the Tone(Noise) generator

Bit 1: C0EN : PSG Channel-0(Tone) enable bit

1 = PSG0 enable
0 = PSG0 disable

Bit 2: C1EN : PSG Channel-1(Tone or Noise) enable bit

1 = PSG1 (Tone or Noise) enable
0 = PSG 1(Tone or Noise) disable

Bit 3: PRBS : Tone or Noise generator selection bit

1 = Noise generator
0 = Tone generator

Bit 6~4: PCK[2~0] : clock source(PSGCK) selection for PSG and DAC

000 = SYSCK / 2
X01 = SYSCK / 4
X10 = SYSCK / 8
011 = SYSCK / 16
100 = SYSCK
111 = OSCX

TABLE 13-28: PSG CONTROL REGISTER (PSGC)

ST2024C

Ver 1.0

32/49

8/4/03

13.4 Noise Generator Control

Noise generator is shown in Figure 12-12., which base
frequency is controlled by PSG1L[5~0].

FIGURE 13-13: Noise Generator Diagram

PSG1L[5~0]

PSGCK

Noise Prescaler

C1N[5~0]

CLOCK

OUTPUT

NCK

CLOCK

OUTPUT

16-Stage White Noise Generator

Noise out

NCK Frequency = PSGCK/(40H-PSG1L[5~0])

13.5 PSG Noise programming

To program noise generator, PSGO (PMCR[1]) or PSGB
(PMCR[0]) should be set to "1" for PB1 or PB0 in order to be
in PSG output. Noise or DAC function is defined by DACE.

Writing a "1" to C1EN will enable noise generator when PSG
is in noise mode.

ST2024C

Ver 1.0

33/49

8/4/03

A built-in digital DAC is for analog sampling data or voice
signals. The structure of DAC is shown in Figure 13-13.
There is an interrupt signal from DAC to CPU whenever DAC
data update is needed and the

same signal will decide the sampling rate of voice. In DAC
mode, the OSC can't less 4 M Hz.

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$00F PMCR R/W

PULL

PDBN

INTEG

PSG0

PSGB

100 - - -00

$012 PSG1L R/W PSG1[7] PSG1[6] PSG1[5] PSG1[4] PSG1[3] PSG1[2] PSG1[1] PSG1[0] 0000 0000
$013 PSG1H R/W

PSG1[11] PSG1[10]

PSG1[9] PSG1[8] - - - - 0000

$014 DAC

R/W DAC[7] DAC[6] DAC[5] DAC[4] DAC[3] DAC[2] DAC[1] DAC[0] 0000

0000

R/W

PCK[2] PCK[1] PCK[0]

PRBS

C1EN C0EN

DACE=0 - 000 0000

$016 PSGC

R/W

PCK[2] PCK[1] PCK[0] DMD[1] DMD[0] INH DACE=1

000

0000

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$014 DAC R/W DAC[7] DAC[6] DAC[5] DAC[4] DAC[3] DAC[2] DAC[1] DAC[0] 0000

0000

Bit 7~0: DAC[7~0] : DAC output data

Note: For Single-Pin Single Ended mode, the effective output resolution is 7 bit.

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

R/W

PCK[2] PCK[1] PCK[0]

PRBS

C1EN

DACE=0 - 000 00-0

$016 PSGC

R/W

PCK[2] PCK[1] PCK[0] DMD[1] DMD[0] INH DACE=1

000

0000

Bit 0: DACE : PSG play as Tone(Noise) or DAC Generator selection bit

1 = PSG is used as DAC Generator
0 = PSG is used as Tone(Noise) Generator

Bit 1: INH : DAC output inhibit control bit

1 = DAC output inhibit
0 = DAC output enable

Bit 3~2: DMD[1~0] : DAC output mode selection

00 = Single-Pin mode : 7 bit resolution
01 = Two-Pin Two Ended mode : 8 bit resolution
10 = Reserved
11 = Two-Pin Push Pull mode : 8 bit resolution

Bit 6~4: PCK[2~0] : PSGCK selection for PSG and DAC

000 = SYSCK / 2
X01 = SYSCK / 4
X10 = SYSCK / 8
011 = SYSCK / 16
100 = SYSCK *
111 = OSCX

* In DAC mode, PSGCK must select SYSCK.

TABLE 14-29: SUMMARY FOR DAC REGISTERS

TABLE 14-30: DAC DATA REGISTER (DAC)

TABLE 14-31: DAC CONTROL REGISTER (PSGC)

ST2024C

Ver 1.0

34/49

8/4/03

14.2 Sampling Rate Control

The sample rate is controlled by PSG1L and PSG1H.
PSG1[11~7] controls sample rate/post scaling and PSG1[6]
must set `0' and PSG1[5~0] must set `1'. The input clock

source is controlled by PCK[2~0]. The block diagram is
shown as the following:

FIGURE 14-14: DAC Generator Diagram

Sample Rate Generator

CK_IN

Enable

Output

PSG[11~0]

PWM Generator

DAC[7~0]

Enable

POB

Reload_DAC

INH

DAC[7~0]

DMD[0]
DMD[1]

PSG[11~0]

PSGCK

BDB

DACE

Reload_DAC

DMD[1]

DMD[0]

FIGURE 14-15: Clock Source for DAC

SYSCK

OSCX

PSGC[6~4]

IN0

IN1

Output

Select

PSG Selector

PSGCK

PSGC

SYSCK/2

PSGCK

SYSCK/4

SYSCK/8

SYSCK/16

SYSCK

OSCX

B6 B5 B4

X
X

0
1
1

0
1

DAC SAMPLE RATE ALGORITHM DESCRIPTION

Sample-Rate = PSGCK / 128 / (20H-PSG1[11~7])

Note: PSG1[6] must set `0' and PSG1[5~0] must set `1' by DAC mode.

TABLE 14-32: Sample Rate description table

ST2024C

Ver 1.0

35/49

8/4/03

14.3 PWM DAC Mode Select

The PWM DAC generator has three modes, Single-pin
mode, Two-pin two ended mode and Two-pin push pull

mode. They are depended on the application used. The DAC
mode is controlled by DMD[1~0]. (TABLE 13-31)

14.3.1 Single-Pin Mode (Accurate to 7 bits)

Single-pin mode is designed for use with a single-transistor
amplifier. It has 7 bits of resolution. The duty cycle of the
PB1 is proportional to the output value. If the output value is
0, the duty cycle is 50%. As the output value increases from
0 to 63, the duty cycle goes from being high 50% of the time

up to 100% high. As the value goes from 0 to -64, the duty
cycle decreases from 50% high to 0%. PB0 is inverse of
PB1's waveform. Figure 13-15 shows the PB1 wave-forms.

FIGURE 14-16: Single-Pin PWM DAC Wave-form

FIGURE 14-17: Single-Pin Application Circuit

PB1

330 ohm

8050

ST2024

SPK

DAC = 0

DAC = 32

DAC = -32

DAC = X

64+X

64-X

High

Low

PB1

ST2024C

Ver 1.0

36/49

8/4/03

14.3.2 Two-Pin Two Ended mode (Accurate to 8 bits)

Two-Pin Two Ended mode is designed for use with a single
transistor amplifier. It requires two pins that PB0 and PB1.
When the DAC value is positive, PB1 goes high with a duty
cycle proportional to the output value, while PB0 stays high.
When the DAC value is negative, PB0 goes low with a duty
cycle proportional to the output value, while PB1 stays low.
This mode offers a resolution of 8 bits.

Figure 13-17 shows examples of DAC output waveforms
with different output values. Each pulse of the DAC is divided
into 128 segments per sample period. For a positive output
value x=0 to 127, PB1 goes high for X segments while PB0
stays high. For a negative output value x=0 to -127, PB0
goes low for |X| segments while PB1 stays low.

FIGURE 14-18: Two-Pin Two Ended PWM DAC Wave-form

FIGURE 14-19: Two-Pin Two Ended mode Application Circuit

PB0

680

8050

ST2024

PB1

SPK

680

.1u

2.2K

Output 1:ON
0:OFF

High

Low

PB0

DAC = X

Where X=0 to 127

DAC = 96

High

Low

PB1

128-X

DAC = 32

DAC = 127

127

High

Low

PB0

DAC = X

Where X=0 to -128

DAC = 0

High

Low

PB1

|X|

128+X

DAC = -48

DAC = -128

ST2024C

Ver 1.0

37/49

8/4/03

14.3.3 Two-Pin Push Pull mode (Accurate to 8 bits)

Two-Pin Push Pull mode is designed for buzzer. It requires
two pins that PB0 and PB1. When the DAC value is 0, both
pins are low. When the DAC value is positive, PB1 goes high
with a duty cycle proportional to the output value, while PB0
stays low. When the DAC value is negative, PB0 goes high
with a duty cycle proportional to the output value, while PB1
stays low. This mode offers a resolution of 8 bits.

Figure 13-19 shows examples of DAC output waveforms
with different output values. Each pulse of the DAC is divided
into 128 segments per sample period. For a positive output
value x=0 to 127, PB1 goes high for X segments while PB0
stays low. For a negative output value x=0 to -127, PB0 goes
high for |X| segments while PB1 stays low.

FIGURE 14-20: Two-Pin Push Pull PWM DAC Wave-form

FIGURE 14-21: Two-Pin Push Pull Application Circuit

PB0

ST2024

Buzzer

PB1

High

Low

PB0

DAC = X

Where X=0 to 127

DAC = 96

High

Low

PB1

128-X

DAC = 32

DAC = 127

127

High

Low

PB0

DAC = X

Where X=0 to -128

DAC = 0

High

Low

PB1

|X|

128+X

DAC = -48

DAC = -128

ST2024C

Ver 1.0

38/49

8/4/03

The ST2024C can drive up to 320 dots of LCD panel directly.
The LCD driver can control by 1/4 duty(160 dots) and 1/8
duty (320 dots). LCD block include display RAM ($200~
$227) for storing the display data, 40-segment output pins
(SEG0~SEG39), 8-common output pins (COM0~COM7).

All LCD RAM are random after power on reset. The bias
voltage circuits of the LCD display is built-in and no external
resistor is needs.

FIGURE 15-22: Clock source of LCD

SYSCK

INTX

SENT

SEL

MUX

SRES-PULSE

SENA

ENABLE

CLEAR

OUTPUT

TCLK

IN0

IN1

TCLK/64

TCLK/32

TCLK/16

TCLK/8

PRES

MUX4-1

IN0

IN3

IN2

IN1

SEL

OUT

LCK[1~0]

IN0

IN1

OSCX

SEL

LCK[2]

OUT

LCD clock

ST2024C

Ver 1.0

41/49

8/4/03

15.4 LCD control register

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$020 LCK R/W

DRV[2] DRV[1] DRV[0] LCK[2] LCK[1] LCK[0] - - 00 0100

$023 PRS R/W SRES SENA SENT

000 - - - - -

$038 XLCD R/W

- HEAV -

- - - - - -0-

$03A LCTL W

LPWR BLANK COMO

LENH

SEGO

CTR[1] CTR[0]

DUTY

0000 0000

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$020 LCK R/W

DRV[2] DRV[1] DRV[0] LCK[2] LCK[1] LCK[0] - -00 0100

Bit 2~0: LCK[2~0] : LCD clock source

LCK[2:0]

Frame Rate

000

OSC / 131072 ( 4MHz / 131072 = 30.5Hz )

001

OSC / 65536 ( 4MHz / 65536 = 61.0Hz )

010

OSC / 32768 ( 4MHz / 32768 = 122.1Hz )

011

OSC / 16384 ( 4MHz / 16384 = 244.1Hz )

1XX

OSCX / 512 ( 32768 / 512 = 64Hz )

***SENA must switch "1". ( refer to FIGURE 14-21 )

Bit 5~3: LCK[5~3] : LCD driving strength control.
The LCD driving strength control will combine HEAV(XLCD[1]) and LENH(LCTL[4]) to select 32 level.

Unit: uA

*** Measure Condition: Vdd=3V, LCD frame rate=64Hz, OSCX: normal load , in WAI1.

LCD driving strength level

HEAV

LENH

DRV[2] DRV[1] DRV[0]

1/4 Duty power

consumption

1/8 Duty power

consumption

LEVEL 0

0 0 0 0 0 14.76 11.64

LEVEL 1

0 0 0 0 1 19.36 15.05

LEVEL 2

0 0 0 1 0 23.83 18.43

LEVEL 3

0 0 0 1 1 28.27

21.77

LEVEL 4

0 0 1 0 0 32.69

24.26

LEVEL 5

0 0 1 0 1

37.1

28.32

LEVEL 6

0 0 1 1 0

41.5

31.68

LEVEL 7

0 0 1 1 1

45.9

LEVEL 8

0 1 0 0 0

50.3

38.37

LEVEL 9

0 1 0 0 1 54.69

41.7

LEVEL 10

0 1 0 1 0 59.09

45.06

LEVEL 11

0 1 0 1 1 63.48

48.4

:
:

LEVEL 28

1 1 1 0 0 138.07 105.1

LEVEL 29

1 1 1 0 1 142.44

108.42

LEVEL 30

1 1 1 1 0 146.84

111.74

LEVEL 31

1 1 1 1 1 151.22

115.06

TABLE 15-33: LCD CONTROL REGISTERS

TABLE 15-34: LCD FREQUENCY REGISTER (LCK)

ST2024C

Ver 1.0

42/49

8/4/03

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$038 XLCD R/W

- HEAV -

- - - - - - 0-

Bit 1: HEAV : LCD driving mode control

1 = Heavy driving mode
0 = Normal driving mode

Address Name R/W

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Default

$03A LCTL W

LPWR BLANK COMO

LENH

SEGO

CTR[1] CTR[0]

DUTY

0000 0000

Bit 7: LPWR : LCD power ON/OFF bit

1 = LCD power OFF
0 = LCD power ON

Bit 6: BLANK : LCD display ON/OFF bit

1 = Disable LCD display (Common line is still scanning)
0 = Enable LCD display

Bit 5: COMO : Output mode for LCD common

1 = COM7~COM4 will be general purpose output only pin
0 = All common output is used as LCD common driver.

Bit 4: LENH : heavy load control for LCD display

1 = Enhanced driving (For large size LCD panel with more power consumption)
0 = Normal driving

Bit 3: SEGO : mode control for LCD segment output

1 = SEG3~SEG0 will be general purpose output pin only
0 = All segment output is used as LCD segment driver

Bit 2~1: CTR[1~0] : LCD Contrast Control

00 = LCD Contrast maximum (level 4)
01 = LCD Contrast level 3
10 = LCD Contrast level 2
11 = LCD Contrast minimum (level 1)

Bit 0: DUTY : LCD duty control bit

1 = 1/8 duty (1/4 bias) *
0 = 1/4 duty (1/3 bias)

* Under 1/8 duty condition with writing a "1" to COMO, LCD output pin COM7~COM4 will be controlled by the SCAN register.
(Please refer to 9.5 Common port)

TABLE 15-35: HEAVY DRIVING LCD MODE CONTROL

TABLE 15-36: LCD CONTROL REGISTER (LCTL)

ST2024C

Ver 1.0

43/49

8/4/03

15.5 LCD RAM map

The LCD RAM map is shown as following:

SEG ADDRESS COM0 COM1 COM2 COM3 COM4 COM5 COM6 COM7

200H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

201H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

202H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

203H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

204H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

205H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

206H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

207H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

208H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

209H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

20AH

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

20BH

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

20CH

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

20DH

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

20EH

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

20FH

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

210H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

211H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

212H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

213H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

214H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

215H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

216H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

217H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

218H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

219H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

21AH

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

21BH

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

21CH

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

21DH

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

21EH

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

21FH

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

220H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

221H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

222H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

223H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

224H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

225H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

226H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

227H

Bit 0

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

Note:

1. The LCD RAM address is allocated at page 2 of memory map. Only bit0 ~ bit3 is useful when it is 1/4 duty

mode.

2. The LCD RAM can be write & read as like general purpose RAM.

TABLE 15-37: LCD RAM MAPPING

ST2024C

Ver 1.0

44/49

8/4/03

The ST2024C has three power down modes: WAI-0, WAI-1
and STP. The instruction WAI will enable mode WAI-0 or
WAI-1, which are controlled by WAIT(SYS[2]). The

instruction WAI (WAI-0 and WAI-1 modes) can be wake-up
by interrupt. However, the instruction of STP can only be
wake-up by hardware reset.

16.1 WAI-0 Mode:

When WAIT is cleared, WAI instruction lets MCU enter
WAI-0 mode. In the mean time, oscillator circuit is be active
and interrupts, timer/counter, and PSG will all be working.
Under such circumstance, CPU stops and the related
instruction execution will stop. All registers, RAM, and I/O
pins will retain their states before the MCU enter standby
mode. WAI-0 mode can be wake-up by reset or interrupt

request. If user disable interrupt(CPU register I='1'), MCU
will still be wake-up but not go into the interrupt service
routine. If interrupt is enabled(CPU register I='0'), the
corresponding interrupt vector will be fetched and interrupt
service routines will executed.
The sample program is showed as followed:

LDA #$00
STA SYS
WAI

; WAI 0 mode

16.2 WAI-1 Mode:

When WAIT is set, WAI instruction let MCU to enter WAI-1
mode. In this mode, the CPU will stop, but PSG,
timer/counter won't stop if the clock source is from OSCX.

The wake-up procedure is the same as the one for WAI-0.
But the warm-up cycles are occur when WAI-1 wake-up.
The sample program is shown as the following:

LDA #$04
STA SYS
WAI

; WAI 1 mode

16.3 STP Mode:

STP instruction will force MCU to enter stop mode. In this
mode, MCU stops, but PSG, timer/counter won't stop if the
clock source is from OSCX. In power-down mode, MCU only

be wake-up by hardware reset, and the warm-up cycles are
occur at the same time.
The sample program is showed as the following:

:
STP
:
:

(SYSCK source from OSC)

Mode

FIGURE

imer1

SYSCK OSC OSCX

Base

Timer

RAM REG. LCD I/O Wake-up

condition

WAI-0

Retain

Reset, Any interrupt

WAI-1 Stop

Stop

Retain

Reset, Any interrupt

STP

Stop Stop Stop

Retain

Reset

(SYSCK source from OSCX)

Mode

FIGURE

imer1

SYSCK OSC OSCX

Base

Timer

RAM REG. LCD I/O Wake-up

condition

WAI-0

Retain

Reset, Any interrupt

WAI-1 Stop

Stop Retain

Reset, Any interrupt

STP

Stop

Stop Retain

Reset

TABLE 16-38: STATUS UNDER POWER DOWN MODE

ST2024C

Ver 1.0

45/49

8/4/03

DC Supply Voltage ----------------------------- -0.3V to +7.0V

Operating Ambient Temperature ----------- -10

�C to +60�C

Storage Temperature ------------------------- -10

�C to +125�C

17.1 DC Electrical Characteristics

Standard operation conditions: V

= 3.0V, GND = 0V, T

= 25

�C, OSC = 4M Hz, OSCX = 32768 Hz,unless otherwise specified

Parameter

Symbol

Min. Typ. Max. Unit

Condition

Operating Voltage

2.4 3 3.6 V

Operating Current

850

1275

�A

All output pins unload, execute NOP instruction,
LCD on

Standby Current 1

SB0

- 0.8

1.2

�A

All output pins unload, OSCX off, LCD off
(WAIT1/STOP mode)

Standby Current 2

SB1

2.85

4.28

�A

All output pins unload, OSCX on(Normal), LCD off
(WAIT1/STOP mode)

Standby Current 3

SB1

4.58

6.87

�A

All output pins unload, OSCX on(Heavy), LCD off
(WAIT1/STOP mode)

Standby Current 4

SB2

- 15 -

�A

All output pins unload, OSCX on, LCD on (level0,
1/4duty) (WAIT1/STOP mode)

Standby Current 5

SB3

- 12 -

�A

All output pins unload, OSCX on, LCD on (level0,
1/8duty) (WAIT1/STOP mode)

Standby Current 6

SB4

- 94

141

�A

All output pins unload, OSCX off, LCD on
(WAIT0 mode)

Input High Voltage

0.7V

- V

+ 0.3

PORT A, PORT B

0.85V

INT

Input Low Voltage

GND

-0.3 - 0.3V

PORT A, PORT B

0.15V

V INT

Pull-up resistance

PORTA, PORTB (IOH = -20uA, VOH=0.7Vdd).

Port A output high
voltage

0.7

V PORTA, PORTB (IOH = -10mA).

Port A output low
voltage

0.3

V PORTA, PORTB (IOL= 4mA).

Port B output high
voltage

0.7

V PORTA, PORTB (IOH = -62mA).

Port B output low
voltage

0.3

V PORTA, PORTB (IOL= 33mA).

SEG output low voltage

OL2

0.3

SEGx,

= 4mA

COM output low oltage

0.3

COMx, I

= 4mA.

Oscillation start time

STT

- 1 3 s

Frequency stability

F / F

PPM

[F(3.0)-F(2.5)]/F(3.0)(crystal oscillator)

Frequency variation

F / F

PPM C1= 15 � 30P.

*Notice:

Stresses above those listed under "Absolute Maximum

Ratings" may cause permanent damage to the device. All the
ranges are stress ratings only. Functional operation of this
device at these or any other conditions above those indicated
in the operational sections of this specification is not implied or
intended. Exposed to the absolute maximum rating conditions
for extended periods may affect device reliability.

ST2024C

Ver 1.0

49/49

8/4/03

Version E1.0 Page41 Adding Measure Condition on TABLE 15-34:

Page 45 Modifying DC Characteristic
Page 47/48 Modifying Application Circuit (1000P 100P)...........................................2003/8/4

Version E0.6 Page45 Modifying FIGURE 17-25: TABLE 17-39:

Page1 Modifying operation voltage 2.4V~3.4V to 2.4V~3.6V.....................................2003/4/16

Version E0.5 Page1 Modifying operation voltage 2.4V~5.2V to 2.4V~3.2V

Page19/20 Modifying SEGs & COMs output HIGH to FLOAT.
Page47/48 Modifying application circuit....................................................................2003/4/4

Version E0.4 -Page40 Filling the LCD power consumption table TABLE 15-34: .

-Page44 Filling the Power consumption table
-Page45 Adding, FIGURE 17-25: ........................................................................2003/2/25

Version E0.3 -Page3 Adding pad location

-Page48 Adding bonding description
-Page41 Modify LCK[2:0] of TABLE 15-34: ..........................................................2002/12/10

Version E0.2 -Page40 Modify the register LCK[2:0].....................................................................2002/10/11

Version E0.1 -Page8 Added DRV[ ] of LCD driving strength in address20H.

-Page40 Added DRV[ ] of LCD driving strength in address20H & Modify TABLE 15-34: ...... 2002/9/2

ST2024C is modified from ST2024

Электронный компонент: ST2024C