HT81XXX

Rev. 1.40

13

March 1, 2005

When voices are playing, the FLAG1 pin outputs a

6Hz signal to drive a LED. The signal is active low,

25% duty. Once the voice output is terminated, the

FLAG1 pin becomes a floating output. When the

FLAG1 and the FLAG2 pins are optioned as 6HzB

and 6Hz outputs, they will alternately output at a

6Hz rate.

When a voice group is playing, the outputs of both

FLAG1 and FLAG2 are turned low, indicating that the

chip is busy.

In addition to the above-stated output signals, FLAG1

can also generate one of the following signals by code

option:

When the voice output is completed, the FLAG1 pin

outputs an active low pulse. The pulse width can be

programmed depending on the customer

¢s require-

ments.

The FLAG1 as well as FLAG2 pins are both floating

outputs when the chip is in the standby state.

Volume Control

The function of the volume control can be set by mask

option. A code is written in the function table for the pur-

pose of controlling the volume of each section output af-

ter the volume control function is chosen. There are two

volume options, namely; full range and half range.

I/O2

The I/O2 pin is a PWM structure. It outputs voice signals

to drive a speaker through an external NPN transistor

when the chip is active. The OUT1 and OUT2 pins are

configured as PWM structure which can drive 8/16/32

W

speaker directly.

@150 is recommended

for an output driver.

A U D

F L A G

: F l o a t i n g

A U D

F L A G

: F l o a t i n g

O U T 1

O S C I

O U T 2

H T 8 1 X X X

S P K

O U T 3

S P K

O S C I

H T 8 1 X X X

A U D

F L A G

: F l o a t i n g