HT81003_02 View Datasheet(PDF) - Holtek Semiconductor
Part Name
Description
Manufacturer
HT81003_02 Datasheet PDF : 8 Pages
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HT81003
Functional Description
The EasyVoiceTM is voice synthesizer with 3-second
voice capacity. A group of pre-recorded voice sections is
played upon receipt of key trigger input signals. Two
FLAG signals are output while playing voices.
The 3-sec voice capacity can be divided into sections of
arbitrary length. Notice that the silence length and
end-pulse width are not included in the memory.
By using Holtek¢s programming tools, the contents and
arrangement of sections, as well as key features and
FLAG output are all programmable before device fabri-
cation.
The IC provides 2 key inputs (KEY1~KEY2), KEY1 can
be optioned as a direct, sequential trigger key. Key 2 can
be selected as a stop or a direct key.
Play function block diagram
K ey
tr ig g e r
K ey
fe a tu re s
o p tio n
8 /1 6 /3 2 W
speaker
K ey
fu n c tio n
V o ic e
ta b le
ROM
ROM
PW M +
PW M -
S e le c t
TR
V DD
8W
speaker
P la y c o n tr o l lo g ic
. la g
o u tp u t
System oscillator
The EasyVoiceTM has a built-in RC oscillator which re-
quires only one external resistor for normal applications.
The oscillator frequency is typically 2MHz for an exter-
nal resistor of 150kW. The required oscillator frequency
may vary with different sampling rates in the process of
voice programming. As a result, the value of the oscilla-
tor resistor may be different with respect to different
items.
O SCI
H T81003
R O SC
The oscillator is turned on when triggered by a key input.
After playing, it is immediately turned off. Then the chip
goes into the standby state.
Voice ROM
The voice ROM is originally designed to continuously re-
cord the 3-sec voice data at about 5kHz sampling rate.
A higher sampling rate will generate voices of better
playback quality, but will shorten the total recording
time. On the other hand, a lower sampling rate will result
in longer recording time but sacrifice the voice quality.
The playback time can be significantly extended by
making use of coding efficiency, silence playing, section
repeating, section cascade, etc.
Section
Section is the basic element constituting the contents of
the voice ROM. During programming, the customer¢s
voice sources can be divided into as many sections as
required. A section can be composed of a voice or an in-
terval of silence. However, the silent length is not
counted in the voice ROM. The total number of sections
included should be less than 256 due to the space limi-
tation of the function table ROM. The total length of the
included sections is limited by the voice ROM.
A section, when triggered by a key input, can be played
once, repeatedly or cascaded with other sections, de-
pending on the key function table instructions.
The following are examples of section division:
E x a m p le 1 : O n e s e c tio n o n ly
s e c .1
ROM
E x a m p le 2 : 3 s e c tio n d iv is io n
s e c .1
s e c .2
s e c .3
ROM
E x a m p le 3 : N s e c tio n d iv is io n
s e c .1 s e c .2
s e c .N
ROM
In addition, a section can be set as retriggerable or
non-retriggerable depending on code option.
· Retriggerable
When the currently playing section is set as
retriggerable, it will stop immediately upon receipt of
other key inputs.
· Non-retriggerable
When the currently playing section is selected as
non-retriggerable, it will go on playing until the whole
section is completed, whether or not there is a key in-
put in the process of playing.
For a key group, some sections can be set as
retriggerable and some as non-retriggerable. When a
retriggerable section of a key group is playing, any key
can be triggered to interrupt its playing. If it is a
non-retriggerable section playing, any key interrupt is
invalid.
Group
The EasyVoiceTM plays groups according to the key in-
put. A group can be made up of one or more sections.
When a key is triggered, the corresponding group is
played. For example, triggering KEY2 plays group 2,
and so on. The same section is allowed to appear in dif-
ferent groups. However, KEY1 can be made up of multi-
ple groups when it is optioned as a sequential key.
Otherwise, each key is composed by one group only.
Rev. 1.10
4
January 22, 2002
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