SNC117
One Channel Direct Drive Speech Controller
1
INTRODUCTION
SNC117 is a one-channel voice synthesizer IC with PWM direct drive circuit. It
built-in a 4-bit tiny controller with one 4-bit input port, two 4-bit I/O ports. By
programming through the tiny controller in SNC117, 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 – 5.1V
40 seconds voice capacity are provided(@6KHZ sample rate)
Built in a 4-bit tiny controller
One 4-bit input port, two 4-bit I/O ports are provided
64*4 bits RAM are provided
128K*10 ROM size are provided for voice data and program
Maximum 16k program ROM is provided
Built in a high quality speech synthesizer
Adaptive playing speed from 2.5k-20kHz is provided
One voice channel
Built in a PWM Direct Drive circuit and a fixed current D/A output
System clock : 2MHz
Low Power Reset
Ver: 1.3
1
June 8, 2005
SNC117
One Channel Direct Drive Speech Controller
3
Block Diagram
ROM
Program/Speech
128K×10 bits
Address Pointers/ STACK
SRAM (64 nibbles)
Timer
ALU
Input port 1
Timing
Generator
OSC
Sampling Rate Counter
PWM
D/A
IO port 3
Voice
Synthesizer
IO port 2
4
PIN ASSIGNMENT
Symbol
P13 ~ P10
P23 ~ P20
P33 ~ P30
VDD
GND
RST
OSC
BUO1/VO
BUO2
I/O
I
I/O
I/O
P
P
I
I
O
O
Function Description
Bit3 ~ Bit0 of Input port 1
Bit3 ~ Bit0 of I/O port 2
Bit3 ~ Bit0 of I/O port 3
Positive power supply
Negative power supply
Reset pin (active high)
Oscillator Input
Positive Output of PWM or DA output
Negative Output of PWM
Ver: 1.3
2
June 8, 2005
SNC117
One Channel Direct Drive Speech Controller
5
FUNCTION DESCRIPTIONS
5.1. Oscillator
SNC117 accepts RC type oscillator for system clock. The typical circuit diagram for
oscillator is listed as follows.
VCC
RC Oscillator
5.2. ROM
SNC117 contains substantial 128K word (10-bit) internal ROM. Program, voices and
other data are shared with this same 128K word ROM.
5.3. RAM
SNC117 contains 64 nibble RAM. The 64 nibble RAM is divided into four pages (page
0 to page 3, 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 3) to switch and indicate the RAM page. Besides, users
can use direct mode, M0 ~ M15 in the data transfer type instructions, to access all 16
nibbles of each page.
5.4. Power Down Mode
“End” instruction will power down SNC117 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 SNC117, any valid data transition (L H or H L)
occurring on any input port (P1) or IO ports (P2 and P3) will lead SNC117 back to
normal operation mode.
5.5. Sampling Rate Counter
The unique sampling rate counter is designed in voice channel to be able to play
diverse voices at different sample playing rates. 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: 1.3
3
r
June 8, 2005
OSC
SNC117
One Channel Direct Drive Speech Controller
5.6. I/O Ports
P1 is a 4-bit input port, P2 and P3 are two 4-bit I/O ports. Any bit of P2 and P3 can
be programmed as either input or output port individually. Any valid data transition
(H L or L H) of P1, P2 and P3 can reactivate the chip when the chip is in
power-down mode.
PAD
To Internal Data Bus
Read Control
Weak
Input Port Configuration (P10~P13)
Port Data
PAD
Port Status
Weak
To Internal Data Bus
Read Control
I/O Port Configuration (P20~P23, P30~P33)
Note: All weak N-MOS’s can serve as pull-low resistors.
Ver: 1.3
4
June 8, 2005
SNC117
One Channel Direct Drive Speech Controller
5.7. DAC & PWM
SNC117 is an advanced chip to be designed having two optimal methods to play
out the voices. One is DAC and the other is PWM. Upon user’s applications, user
can select either DAC or PWM in his design. Please be aware that only one
method can be activated at a time.
DAC:
A 7-bit current type digital-to-analog converter is built-in SNC117. The
relationship between input digital data and output analog current signal is listed
in the following table. Also, the recommended application circuit is illustrated as
follows.
Input data
0
1
…
N
…
127
Typical value of output current (mA)
0
3/127
n*(3/127)
3
VCC
BUO1/VO
1K
DAC output
Ver: 1.3
5
June 8, 2005
stm32/stm8
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