
6F-3 NO.7, LANE 75, TA-AN ROAD, SEC.1, TAIPEI, TAIWAN, R.O.C.
http://www.aplusinc.com.tw
台北市大安路一段75巷7號6F-3 TEL:886-2-27818277 FAX:886-2-27815779

ASM2012C – VERY LOW-COST VOICE SYNTHESIZER WITH 4-BIT MICROPROCESSOR
1.0 General Description
The ASM2012C is very low cost voice synthesizer with 4-bit microprocessor. It has various features
including 4-bit ALU, ROM, RAM, I/O ports, timers, clock generator, watchdog timer(WDT), voice
synthesizer, etc. It consists of 22 instructions in the device. With CMOS technology and halt function
can minimize power dissipation. Its architecture is similar to RISC, with two stages of instruction
pipeline. It allows all instructions to be executed in a single cycle, except for program branches and
data table read instructions (which need two instruction cycles).
1.1 Feature
u Single power supply can operate from 2.4V through 5V
u Internal Program ROM: 4K x 10-bit
u 1 sets of 16-bit DPR can access up to 64K x 10 bits data memory space
u Data Registers:
• 96 x 4-bit data RAM (00-1Fh plus 40h-7Fh)
• Unbanked special function registers (SFR) range: 20h-3Fh
u I/O Ports:
• PRA: 4-bit I/O Port A (2Bh)
• PRB: 4-bit Output Port B (2Dh)
• PRC: 4-bit Input Port C (2Fh)
u On-chip clock generator: Resistive Clock Drive(RM)
u Timer: 1
• Timer0: a 9-bit auto-reload timer/counter
u Stack: 2-level subroutine nesting
u HALT and Release from HALT function to reduce power consumption
u Watch Dog Timer (WDT)
u Instruction: 1-cycle instruction except for table read and program branches which are 2-cycles
u Number of instruction: 22
1
Rev 1.0

FIGURE 1.1 : Block Diagram of ASM2012C
Data Bus[3:0]
(ADDR[15:12])
=0000b
COUT
PCLATCH(8)
DPR3,2,1
DLATCH(10)
ALU(4)
Register(4)
One-Channel
( Voice synthesizer )
COUT
PC[11:0]
ADDR[15:0]
DPR[15:0]
P1,P2,P3,P4
enter test mode
Reset Chip
Reset Chip
(2-Level)
ROM_ADDR[15:0]
ROM_Data[9:0]
SRAM
(96 x 4)
00h-1Fh
40h-7Fh
Test select
Power on Reset
RESET pin
Program
(Data)
ROM
Instruction Bus [9:0]
Instruction Bus [9:0]
Timer0(9)
OSC
VDD/GND
PRA0
ROM Latch
Latch
Decoder
Control Signal
Instruction Bus [9:0]
PRA(4)
PRB(4)
PRC(4)
weak or strong
pull-low for PRA,
PRB, PRC
PRASL(4)
2
Rev 1.0

FIGURE 1.2 : External ROM Map of ASM2012C
PC[11:0]
12bit x 2 STACK
00000h-0FFFFh
16-bit Data Pointer
Reserved for Testing
Program and data ROM
Data ROM
Reset Vector
00000h
00080h
00080h-003FFh
00400h
00000h-00FFFh
00FFFh(4K)
0FFFFh(64Kx10-bits)
3
Rev 1.0

1.2 Pin-Out
ASM2012C Pin-Out
PRC1 I STI
Std./O.D.
PRC0/RESET
PRA3-1 I/O STI
PRA0/RESET
OSC I - RM mode Oscillator input
VDD1 I - First Power supply during operation
COUT O - Current Output of Audio
GND1 I - First Circuit Ground Potential
GND2 I - Second Circuit Ground Potential
TEST O - Enter Test Mode. ( TEST = High )
VDD2 I - Second Power supply during operation
PRB0-3 O Std./O.D. Output type with standard or Open-Drain output
PRC2-3 I STI
I STI
Std./O.D.
Std./O.D.
I/O STI
Std./O.D.
Std./O.D.
Input port with programmable strong pull-low or weak pull-low or fix-inputfloating capability
Input port with programmable strong pull-low or weak pull-low or fix-inputfloating capability
Mask option selected as an external RESET pin with weak pull-low capability
I/O port with programmable strong pull-low or weak pull-low or fix-inputfloating capability
Output type with standard or Open-Drain output
I/O port with programmable strong pull-low or weak pull-low or fix-inputfloating capability
Output type with standard or Open-Drain output
Mask option selected as an external RESET pin with weak pull-low capability
Input port with programmable strong pull-low or weak pull-low or fix-inputfloating capability
1.3 Application circuit
4
Rev 1.0

1.4 Bonding Diagram
19 18 17 16 15 14 13 12
RC3 RC2 RC1 RC0 GND2 VDD2 TEST AOSC
( 64K x 10-bit ) Block ROM
ASM2012C
RA3 RA2 RA1 RA0 VDD1 COUT GND1 RB0 RB1 RB2 RB3
1 2 3 4 5 6 7 8 9 10 11
ASM2012C Pad Location Chip Size: X=1540+80 (um), Y=1780+80 (um)
PAD # PAD Name X Y PAD # PAD Name X Y
1 RA3
2 RA2
3 RA1
4 RA0
5 VDD1
6 COUT
7 GND1
8 RB0
9 RB1
10 RB2
-682.16 -772.68
-559.84 -772.68
-437.52 -772.68
-315.2 -772.68
-191.28 -772.68
71.12 -772.68
189.52 -772.68
307.92 -772.68
430.24 -772.68
552.56 -772.68
11 RB3
12 AOSC
13 TEST
14 VDD2
15 GND2
16 RC0
17 RC1
18 RC2
19 RC3
667.68 -772.68
633.56 804
432.48 804
273.16 804
134.68 804
-51.76 804
-248.4 804
-454.24 804
-650.88 804
5
Rev 1.0

1.5 DC Characteristics for ASM2012C
SYMBOL PARAMETER VDD MIN. TYP. MAX. UNIT CONDITION
VDD
Isb
Iop
Iih
Ioh
Iol
dF/F
dF/F Fosc VARIATION -20 20 %
OPERATING
VOLTAGE
SUPPLY
CURREN
T OPERATING
INPUT CURRENT
/Internal pull low
OUTPUT HIGH
CURRENT
OUTPUT LOW
CURRENT
FREQUENCY
STABILITY
STANDBY
2.4 3 5 V depending on Freq.
3 1
5 1
3 2
5 7
3 3
5 9
5 -5.2
3 -3
5 -8
3 7
5 20
-10 10 %
uA
mA
uA
mA
4MHz, RM
in HALT Mode
4MHz, RM
IO Floating
4MHz, RM
in HALT Mode
(IO Ports with
weak pull-high
4MHz, RM
Fosc(2.4v)
VDD=3V,
Rosc=220k, 4MHz
pull-low)
(IO ports)
Fosc(3v)-
Fosc (3v)
FIGURE 1.3 : Frequency Range for Rosc in RM mode
Resistor(k ohm) 330 220 200 150
3v Freq.(MHz) 2.68 4.11 4.7 5.94
Rosc & Freq.
8
6
4
Freq. MHz
2
0
0 100 200 300 400
5.94
Rosc k ohm
4.7
4.11
2.68
6
Rev 1.0