LG CG225 Service Manual page 41

3. H/W Circuit Description
MIDI SOUND circuit description
MCLK
The YMU792 has features as described below.
• Simultaneous generation of up to 64 tones:
• Voice Synthesis function by HV Synthesizer.
• Time Fluctuation Low-pass Filter function by AL Synthesizer.
• ADPCM/PCM stream playback.
• Default voices for FM and Wave Table synthesizer are in a ROM, and voice registration to
SRAM is possible.
• Digital Audio Input function. (Valid only for slave mode.)
• Digital Audio Output function. (Fixed to Fs=48 kHz. Valid only for master mode.)
• Speaker Amplifier and Equalizer circuit are integrated.
• Stereo head phone amplifier and bus boost circuit are integrated.
• External output amplifier is integrated.
• PLL is integrated. Master clock input up to 27 MHz is available. TCXO available
• 16-bit stereo D/A converter is integrated.
MIDI
V_IO
1V8_MIDI
U206
TC7SH08FS C205 0.1u
5
1
VCC
4
C209
3 1000p
GND
2
D3
_RST
E2
CLKI
D2
R204 NA PLLC
H4
_MIDI_CS _CS__SS
F1
R205 6.8K
A(1) A0
E3
A(2) A1
J5
_WR _WR_SCK
C213 C214
G4
_RD _RD_SI
2200p 100p
G3
D(0) D0
J2
D(1) D1
H2
D(2) D2
G2
D(3) D3
H1
D(4) D4
J1
D4_H1
F3
D(5) D5
G1
D(6) D6
F2
D(7) D7
J6
SO
H5
SMODE
G5
IFSEL
G7
VIBRATOR MTR
J8
MTR_G7
H8
LED0
H7
LED1
J7
LED2
E7
MELODY_INT _IRQ
H6
GPIO
G8
BCLK
F7
LRCK
F8
SDIN
E6
MCLK
D6
TESTI0
F6
TESTI1
G6
TESTI2
C7
TESTI3
Figure 21. MIDI sound Circuit
1V8_MIDI V_IO VBAT
C202 10u C203 10u C204 4.7u
C206 0.1u
C207 0.1u C208 0.1u
C210 0.1u
C2
TXOUT
A2
EXC
C6
EXTOUT
B5
BBL
B6
HPOUTL
C5
BBR
A6
HPOUTR
U201
YMU792
B3
HPC
C223
B4
EQ1
A3
EQ2
A4
EQ3
A7
SPOUT2
B7
SPOUT1
A8
SPOUT1_B7
R213
C3
RXIN
A1
RXIN_C3
C4
EXTIN
D4
INDEX
- 40 -
22n R208
39K
R209 120K
C227 47p
33K
C228 1u
C229
47p