HT813D0 datasheet(4/12 Pages) HOLTEK

4 / 12 page

Functional Description

The HT813D0 is a mask ROM type voice synthe-

sizer with 5.6-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 5.6-second voice capacity can be divided into

sections of arbitrary length. Notice that the si-

lence length and end-pulse width are not in-

cluded 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 pro-

grammable before device fabrication.

The IC provides 8 key inputs (KEY1~KEY8). Of

the 8 keys, KEY1 can be optioned as a direct,

sequential or random trigger key. KEY8 can be

selected as a stop or a direct key. The remaining

6 keys (KEY2~KEY7), are used as direct keys

exclusively.

Play function block diagram

System oscillator

The HT813D0 has a built-in RC oscillator which

requires only one external resistor for normal ap-

plications. The oscillator frequency is typically

96kHz for an external resistor of 530k

Ω. The re-

quired oscillator frequency may vary with differ-

ent sampling rates in the process of voice

programming. As a result, the value of the oscilla-

tor resistor may be different with respect to differ-

ent items.

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 continu-

ously record the 5.6-second voice data at about

6kHz 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 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 program-

ming, the customer’s voice sources can be di-

vided into as many sections as required. A

section can be composed of a voice or an interval

of silence. However, the silent length is not

counted in voice ROM. The total number of

sections included should be less than 380 due to

the space limitation of the function table ROM.

The total length of the included sections is lim-

ited by the voice ROM.

A section, when triggered by a key input, can be

played once, repeatedly or cascaded with other

sections, depending on the key function table

instructions.

HT813D0

5th May ’98

HT813D0 Datasheet(PDF) 4 Page - Holtek Semiconductor Inc

HT813D0 Datasheet(HTML) 4 Page - Holtek Semiconductor Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12

Datasheet Download

Link URL