HT3421A
41 Matrix Key Multi-Function Piano with a Memory
Pin Assignment
Features
Operating voltage: 2.4V~5V
System operating frequency: 512KHz
12
7 matrix input keys
Auto power-off
Power ON/OFF toggle input
41 tones, tone area: G2~B5
8 rhythms
8 timbres
16 steps of tempo speed
4 pulsatile sounds
12 demo songs
Memory function with 62 notes
40 pin dual-in-line package
General Description
The HT3421A is a 41-key musical instrument
LSI implemented in the CMOS technology. The
chip provides 8 rhythms, 8 timbres, 4 pulsatile
sounds, 12 demo songs, and a 62-note memory
storage function. The 12
7 matrix control keys
of the HT3421A control both basic keys and
function selection inputs.
In the Memory mode, the chip can store a tone
of 62 notes. Pressing of the Replay key plays the
stored songs, or pressing of OKP1 or OKP2
plays the stored songs tone by tone.
In the Demo mode, one of the 12 demo songs can
be played. The timbre of the demo song can also
be altered according to the instrument chosen.
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28th June '96
Pad Coordinates
Unit: mil
Pad No.
X
Y
Pad No.
X
Y
1
82.17
100.34
21
82.85
100.60
2
82.90
11.99
22
82.85
92.95
3
82.90
28.56
23
82.85
82.24
4
82.90
36.38
24
82.85
72.55
5
82.90
44.03
25
82.85
64.90
6
82.90
51.64
26
82.85
50.11
7
82.90
63.33
27
83.19
42.20
8
82.90
81.26
28
83.70
0.81
9
82.90
92.95
29
83.70
8.80
10
82.90
100.60
30
83.70
27.84
11
70.32
100.60
31
82.85
100.00
12
7.67
100.60
32
69.08
100.34
13
1.93
100.60
33
61.01
100.34
14
11.54
100.60
34
52.93
100.34
15
21.14
100.60
35
2.61
100.68
16
30.75
100.60
36
14.22
100.68
17
40.35
100.60
37
40.65
100.68
18
50.00
100.60
38
56.80
100.68
19
59.56
100.60
39
66.24
100.34
20
69.17
100.60
40
73.97
100.34
Pin Description
Pin No. Pin Name
I/O
Internal
Connection
Description
1
OUT
O
Transmission
Gate
Tone output
2
ENV
O
CMOS
Envelope effect output
3
TEST4
--
--
For IC test only
4
TEST3
--
--
For IC test only
5
S/H
O
PMOS
Open Drain
Snare-Drum or Hi-Hat pulsatile sound output
6
B/C
O
PMOS
Open Drain
Bass-Drum or Cow-Bell pulsatile sound output
7
VIB
O
CMOS
Vibrato ON: VIB provides a 4Hz signal output.
Vibrato OFF: VIB is a low-level output.
8~14
C7~C1
O
NMOS
Open Drain
Matrix control key scanning outputs
HT3421A
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28th June '96
Pin No. Pin Name
I/O
Internal
Connection
Description
15~26
R1~R12
I
CMOS
Pull-High
Matrix control key scanning inputs
27
TEST5
--
--
For IC test only
28
TEST2
--
--
For IC test only
29
MEMO
I
CMOS
Pull-High
Connect this pin to VSS/VDD to work in either the
memory or play mode.
30
TEST1
--
--
For IC test only
31
RESET
I
CMOS
Pull-High
Power on reset
32
ON/OFF
I
CMOS
Pull-High
At power on, the system is in the OFF state. Press
the ON/OFF key to alternate the system from OFF
to ON or vice versa. When power is auto off, there
will be no tone output for 5 minutes.
33
BUSY
O
CMOS
BUSY is high while the system is operating, but low
when the system is in the stand-by state.
34
VSS
I
--
Power supply (ground)
35
MODE
I
CMOS
Pull-High
Toggle selection of play mode or memory mode
The system is in the play mode at power-on.
36
OSC1
I
--
Oscillator input
37
OSC2
O
--
Oscillator output
38
MLED
O
NMOS
Open Drain
Memory mode indication output
39
TLED
O
NMOS
Open Drain
Tempo indication output
40
VDD
I
--
Power supply (positive)
Absolute Maximum Ratings
Supply Voltage .............................. 0.3V to 5.5V
Storage Temperature................. 50
C to 120
C
Input Voltage................. V
SS
0.3V to V
DD
+0.3V
Operating Temperature................... 0
C to 70
C
HT3421A
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28th June '96
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