This particular application (Allophone Set)
requires only six address Pins (A1-A6) to
address all the 69 allophones plus five
pauses, a total of 64 locations. For
simplicity, since only six address pins are
needed to address the 64 locations, pins A7
and A8 can be tied low (to ground) and now
any further references to the address bus
will Include A1-A6 end A7=A8=0
There are two modes available for loading an
address into the chip. SE (Strobe Enable)
controls the mode that will be used.
Mode 0 (SE=0) will latch is an address when
any one or more of the address pins makes
a low to high transition. For example, to load
the address one (1), A2 to A6=0 and A1 is
pulsed high. To load the address twelve (12
octal), A1=A3=A5=A6=0, A2 and A4 are
pulsed high simultaneously. (Note that an
address of zero cannot be loaded using this
mode).
Mode 1 (SE=1) will latch in an address using
the ALD pln. First, setup the desired
address on the address bus (A1-A6) and
then
low. Any address can be loaded using this
mode, but certain setup and hold times are
then pulse ALD required (refer to the
attached timing diagram for the specific
times).
Two microprocessor interface pins are
available for quick loading of addresses.
They are LRQ and SBY. LRQ (Load
Request) tells the processor when the input
buffer is full. SBY (Stand By) tells the
processor that the chip has stopped talking
and no new address has been loaded. Either
interface pin can be used when
concatenating allophones. LRQ is an active
low signal, when LRQ goes low it is time to
load a new address to the chip. If LRQ is
high, then simply wait for It to go low before
loading the address. SBY will stay high until
an address is loaded, then it will go low and
stay low until all the internal instructions
(Speech Code) from that one address are
completed. Once this signal goes high, It is
time to load a new address. Since speech
does not require very fast address loading, it
would be acceptable to use SBY to interface
to the processor.
SPO256 BLOCK DIAGRAM
C1
C2
C3
SER
OUT
EXTERNAL ROM
CONTROL
ALU
SER
IN
DATA
2K x 8 BIT
ROM
ROM DISABLE
ROM CLOCK
SERIAL COEFFICIENT TRANSFER
SOURCE AND
INTERPOLATION
(5 REGISTERS)
8 BITS
12 HOLDING
REGISTERS
(COEFFICIENTS)
8 BITS
VOCAL TRACT MODEL
(12 POLE DIGITAL
FILTER)
7 BITS
PULSE WIDTH
MODULATOR
DIGITAL
OUT
ADDRESS
REGISTER
START ADDRESS
LATCH
HANDSHAKE
CONTROL
OSC
OSC 2
OSC 1
ALD SE LRQ SBY
A8 8 BIT A1
ADDRESS
SBY RESET
VD1
2
To end a word using allophones it is
necessary to load a pause to complete the
word. For example, the word “TWO”
thenistosimo
ELECTRICAL CHARACTERISTICS
Maximum Ratings*
All pins with respect to Vss.........-0.3 to 8.0V
Storage Temperature.............-25°C to 125°C
Standard Conditions
Clock - Crystal Frequency ............3.120 MHz
Operating Temperature (Ta).......0°C to 70°C
DC CHARACTERlSTlCS/SPO 256
can be implemented using the following
allophones, TT2-VW2-PA1. PA1 is actually
not an allophone but a pause which is
needed to end the word.
*Exceeding these ratings could cause permanent
damage to the device. This is a stress rating only and
functional operation of this device at these conditions
is not im-plied. Operating ranges are specified in
Standard Condi-tions. Exposure to absolute
maximum rating conditions for extended periods may
affect device reliability.
Data labeled "typical" is presented for design
guidance only and is not guaranteed
Characteristic
Sym Min Typ Max Units
Conditions
Supply Voltage
Supply Current
VDD 4.6
VD1 4.6
IDD
ID1
INPUTS
A1-A8, ALD, SERIN, TEST, SE
LOGIC 0
LOGIC 1
CAPACITANCE
LEAKAGE
V IL
V IH
CIN
IL
RESET, SBY RESET
LOGIC 0
LOGIC 1
V IL
V IH
OUTPUTS
SBY, Digital Out, C1, C2, C3,
LRQ, ROM DIS, ROM CLK,
SEROUT
LOGIC 0
LOGIC 1
VOL
VOH
0.0
2.4
0.0
3.6
0.0
2.5
OSCILLATOR
OSC 2 (Output)
LOGIC 0
LOGIC 1
VOL 0.0
VOH 2.5
7.0 V
7.0 V
90 mA TA = 25ºC, VD1 , VDD = 7.0V
Reset & SBY Reset high.
All outputs floating.
21 mA Same as above.
0.6
VD1
V
V
10 pF
+10 µa
0 Volts bias, f = 3.12 MHz
VPIN = 7.0V Other Pins = 0.0V
0.6
VD1
V
V
0.6
VD1
V
V
I OL = 0.72ma (2LS TTL Loads)
IOH = -50 µa (2LS TTL Loads)
0.6
VD1
V
V
When driven from external source.
OSC 1 (Input) = 3.90 V MIN
OSC 1 (Input) = 0.60 V MAX
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