SNC20AS
Direct Drive Speech Controller
================= CONTENTS ================
1.
2.
3.
4.
5.
5.1.
5.2.
5.3.
5.4.
5.5.
5.6.
5.7.
5.8.
6.
7.
8.
INTRODUCTION........................................................................................................2
FEATURES ..................................................................................................................2
BLOCK DIAGRAM ....................................................................................................3
PIN ASSIGNMENT.....................................................................................................3
FUNCTION DESCRIPTIONS ...................................................................................4
O
SCILLATOR
...............................................................................................................4
ROM ..........................................................................................................................4
RAM ..........................................................................................................................4
P
OWER
D
OWN
M
ODE
..................................................................................................4
S
AMPLING
R
ATE
C
OUNTERS
.......................................................................................4
E
VENT
M
ARK
..............................................................................................................5
I/O P
ORTS
...................................................................................................................5
DAC & PWM.............................................................................................................6
ABSOLUTE MAXIMUM RATING ..........................................................................8
ELECTRICAL CHARACTERISTICS .....................................................................8
APPLICATION CIRCUIT .........................................................................................9
DISCLAIMER .....................................................................................................................11
Ver: 0.3
1
Sept 20, 2007
SNC20AS
Direct Drive Speech Controller
1.
INTRODUCTION
SNC20AS is a single channel voice synthesizer IC with PWM direct drive circuit. It
built-in a 4-bit tiny controller with six I/O pins. By programming through the tiny
controller in SNC20AS, user’s varied applications including voice section combination,
key trigger arrangement, output control, and other logic functions can be easily
implemented.
2.
FEATURES
Single power supply 2.4V – 5.5V
85 seconds voice capacity are provided (@6KHZ sample rate)
Built in a 4-bit tiny controller
Where P3.2, P3.3 can direct drive LED (8mA for driving, 16mA for sink)
Six I/O pins are provided (P3.0~P3.3, P2.0, P2.1)
48*4 bits RAM are provided
256K*10 ROM size are provided for voice data and program
Maximum 16K program ROM is provided
Readable ROM code data
Built in a high quality speech synthesizer
Adaptive playing speed from 2.5k-20kHz is provided
Built in a PWM Direct Drive circuit and a fixed current D/A output
8-level volume control for PWM Direct Drive output
System clock: 2MHz
Low Power Detect
Ver: 0.3
2
Sept 20, 2007
SNC20AS
Direct Drive Speech Controller
3.
Block Diagram
ROM
Program/Speech
256K×10 bits
Timing
Generator
Address Pointers/ STACK
SRAM (48 nibbles)
Timer
ALU
IO3 / IO2
OSC
Sampling Rate Counter
Voice
Synthesizer
PWM
D/A
4.
PIN ASSIGNMENT
Symbol
P33 ~ P30
P21 ~ P20
VDD
GND
RST
OSC
BUO1/VO
BUO2
Fuse
I/O
I/O
I/O
P
P
I
O
O
O
I
Function Description
Bit3 ~ Bit0 of I/O port 3
Bit1 ~ Bit0 of I/O port 2
Positive power supply
Negative power supply
Reset pin (active high)
Oscillator / Crystal Out
Positive Output of PWM or DA output
Negative Output of PWM
For test mode
Ver: 0.3
3
Sept 20, 2007
SNC20AS
Direct Drive Speech Controller
5.
FUNCTION DESCRIPTIONS
5.1. Oscillator
SNC20AS accept RC type oscillator for system clock. The typical circuit diagram for
oscillator is listed as follow.
VCC
OSC
RC Oscillator
5.2. ROM
SNC20AS contains substantial 256K words (10-bit) internal ROM. Program, voices
and other data are shared with this same 256K words ROM.
5.3. RAM
SNC20AS contains 48 nibbles RAM. The 48 nibbles RAM are divided into three
pages (page 0, page 1 and page 2, 16 nibble RAM on each page). In our programming
structure, users can easily define and locate RAM page in the program. For instance,
users can use the instructions, PAGEn (n=0 to 2) to switch and indicate the RAM page.
Besides, users can use direct mode, M0 ~ M15 in the data transfer type instructions
(M15 is forbidden using for user in each page), to access all 16 nibbles of each page.
5.4. Power Down Mode
“End” instruction will power down SNC20AS and enable IC to consume fewer current
for power saving. (<3uA @VDD=3V and <5uA @VDD=5V) Please be aware that
when the power down mode is activated in SNC208, any valid data transition (L H or
H L) occurring on any IO pins of P3 and P2 will lead SNC20AS back to normal
operation mode.
5.5. Sampling Rate Counters
The playing rate can be adaptively set up among from the wide ranges of 2.5KHz to
20KHz. This feature makes voice close to its original source and yield the better voice
quality.
Ver: 0.3
4
r
Sept 20, 2007
SNC20AS
Direct Drive Speech Controller
5.6. Event Mark
This is a new function for SNC20AS, it allows user to add a special mark in wave data
by the voice edit tool “CoolEdit”. User can insert event tags in anywhere of his wave
file and can easy to get this special code to do his special action during voice playing.
That means, it should be easily to control the I/O (such as LED or motor) and other
actions to synchronize with voice.
5.7. I/O Ports
P30~P33 and P20~P21 are I/O pins. Any bit of them can be programmed as either
input or output port individually. Any valid data transition (H L or L H) of P30~P33
and P20~P21 can reactivate the chip when the chip is in power-down mode.
Port Data
PAD
Port Status
Weak
To Internal Data Bus
Read Control
I/O Port Configuration (P30~P33, P20~P21)
Note:
(1) Weak N-MOS’s can serve as pull-low resistors.
(2) The driving and sink current of P3.2 and P3.3 are enhance to be 8mA/16mA.
So user can direct to drive the LED through those two I/O pins.
Ver: 0.3
5
Sept 20, 2007
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