FT800 Datasheet, PDF (27/55 Pages) Future Technology Devices International Ltd. – Embedded Video Engine

4.6 Audio Engine
Document No.: FT_000792
FT800 Embedded Video Engine
Datasheet Version 1.1
Clearance No.: FTDI# 334
FT800 provides mono audio output through a PWM output pin, AUDIO_L. It outputs the two
audio sources, the sound synthesizer and audio file playback.
4.6.1 Sound Synthesizer
A sound processor, AUDIO ENGINE, generates the sound effects from a small ROM library of
waves table. To play a sound effect listed in Table 4.3, load the REG_SOUND register with a
code value and write 1 to the REG_PLAY register. The REG_PLAY register reads 1 while the
effect is playing and returns a ‘0’ when the effects end. Some sound effects play continuously
until it is interrupted or commanded to play the next sound effect. To interrupt an effect, write
a new value to REG_SOUND and REG_PLAY registers; e.g. write 0 (Silence) to REG_SOUND
and 1 to PEG_PLAY to stop the sound effect.
The sound volume is controlled by register REG_VOL_SOUND. The 16-bit REG_SOUND register
takes an 8-bit sound in the low byte. For some sounds, marked "pitch adjust" in the table
below, the high 8 bits contain a MIDI note value. For these sounds, note value of zero
indicates middle C. For other sounds the high byte of REG_SOUND is ignored.
Table 4-12 Sound Effect
Value
Effect
Conti
nuous
00h
Silence
Y
01h
square wave
Y
02h
sine wave
Y
03h sawtooth wave
Y
04h triangle wave
Y
05h
Beeping
Y
06h
Alarm
Y
07h
Warble
Y
08h
Carousel
Y
10h
1 short pip
N
11h
2 short pips
N
12h
3 short pips
N
13h
4 short pips
N
14h
5 short pips
N
15h
6 short pips
N
16h
7 short pips
N
17h
8 short pips
N
18h
9 short pips
N
19h 10 short pips
N
1Ah 11 short pips
N
1Bh 12 short pips
N
1Ch 13 short pips
N
1Dh 14 short pips
N
1Eh 15 short pips
N
1Fh 16 short pips
N
23h
DTMF #
Y
2Ch
DTMF *
Y
30h
DTMF 0
Y
31h
DTMF 1
Y
Pitch
adjust
N
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
N
N
N
N
Value
32h
33h
34h
35h
36h
37h
38h
39h
40h
41h
42h
43h
44h
45h
46h
47h
48h
49h
50h
51h
52h
53h
54h
55h
56h
57h
58h
60h
61h
Effect
DTMF 2
DTMF 3
DTMF 4
DTMF 5
DTMF 6
DTMF 7
DTMF 8
DTMF 9
harp
xylophone
tuba
glockenspiel
organ
trumpet
piano
chimes
music box
bell
click
switch
cowbell
notch
hihat
kickdrum
pop
clack
chack
mute
unmute
Conti
nuous
Y
Y
Y
Y
Y
Y
Y
Y
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
Pitch
adjust
N
N
N
N
N
N
N
N
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
N
N
N
N
N
N
N
N
N
N
N
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