HT81003 datasheet(5/8 Pages) HOLTEK

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HT81003

Rev. 1.10

January 22, 2002

Key function table

The voice ROM sections are played according to the in-

structions of the key function table. The function table

contains group information and the playing order of the

sections in the groups. Notice that the total amount of

sections included in the groups should be less than 256

which is the space limitation of the function table ROM.

· KEY1 as a direct key

Each key is mapped to a group in the function table. If

a key is not used, the group mapped to that key is a

piece of silence. The following is an example of the

function table:

Group 1

sec.1 + sec.2 + sec.3 + sec.4

Group 2

sec.3

As illustrated in the table, voice ROM is composed of 4

sections, and 5 sections for the function table. If KEY1

is momentarily triggered, section 1, section 2, section

3 and section 4 are played in sequence and then

stopped. Triggering KEY2 plays section 3.

· KEY1 as a sequential key

When KEY1 is optioned as a sequential key, it can in-

clude multiple groups (sub-groups) in the function ta-

ble. However, KEY2 is used as a direct key exclusively

and comprise of only one group in the function table.

An example is shown below:

Group 1-1

sec.4 + sec.2

Group 1-2

sec.1 + sec.3

Group 1-N

sec.2 + sec.3

Group 2

sec.2 + sec.3

As indicated in the above table, KEY1 can be made up

of sub-groups. The corresponding sub-groups is

played in sequence each time KEY1 is triggered.

¨ The playing sequence of sequential KEY1 is: Group

1-1

® Group 1-2 ® Group 1-3 ..... ® Group 1-N

(the last group)

® Group 1-1 .....

¨ Reset of KEY1 playing sequence

If a sub-group of KEY1 group is being played and

KEY2 is triggered, the playing sub-group will be ter-

minated, and the newly triggered key group is played

in stead. The first sub-group will start playing by

retriggering KEY1. In other words, the KEY1 playing

sequence is reset whenever a key other than KEY1

is triggered (see Figure 1).

¨ Sub-group selection

When KEY1 is triggered with pulses, a desired

sub-group can be selected by controlling its corre-

sponding pulse number. However, the features of

KEY1 have to be set in the following ways:

- sequential

- retriggerable

- minimum key debounce time (

@1.2ms, fOSC=2MHz)

For instance, if sub-group 1-3 is the previous playing

group, sub-group 1-5 will start playing after 2 pulses

are applied to KEY1, and so on.

To make a selection of KEY1 sub-groups more easy,

KEY2 should be programmed as silence. Then this si-

lence key has to be triggered to reset KEY1. By so do-

ing, the playing sub-group of KEY1 is directly

specified by the pulse number applied to KEY1 (see

Figure 2).

· KEY2 as a stop key (by mask option)

When KEY2 functions as a stop key, any voice output

can be stopped by pressing KEY2.

G r o u p 1 - 1

G r o u p 1 - 2

G r o u p 1 - N

G r o u p ( 2 ~ 8 )

G r o u p 1 - 1

K E Y 1

K E Y 2

A U D

Figure 1. Reset of KEY1 playing sequence

G r o u p 1 - N

N p u l s e

G r o u p 1 - M

M p u l s e

K E Y 1

K E Y 2

( S i l e n c e )

A U D

Figure 2. KEY1 sub-group selection

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