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DAC (UPD6376CX)
UPD6376CX is a two-channel 16-bit Digital to Analog Convertor consisting of resistor string, output
amplifier and zero offset circuit.
Key Touch LSI (HG52E35P)
By counting the time between first-key input signal FI and second-key SI from the keyboard unit, the key
touch LSI detects key velocity of 256-step. Then the LSI sends the CPU the note number and its velocity
data.
RESB
CCSB
CWRB
CRDB
CKI
CD0
CD7
CA0 ~ CA2
First contact
Second contact
KC0
KC7
FI0
FI7
SI0
SI7
Key input signal
Key scan signal
~
Data bus
Address bus
Reset signal from the CPU
Chip select signal from the gate array
Read enable signal from the gate array
Write enable signal from the gate array
Clock from the gate array
Key touch LSI
HG52E35P
Keyboard
FI
SI
KC
Pin No. Terminal In/Out Function
1 SEL In Mode selection terminal. Connected to ground.
2 D.GND In Ground (0V) source for internal digital circuit
3 NC Not used.
4 DVDD In +5V source for internal digital circuit
5 A.GND In Ground (0V) source for internal analog circuit
6 R.OUT Out Sound waveform output
7 A.VDD In +5V source for internal analog circuit
8 A.VDD In +5V source for internal analog circuit
9 R.REF In Reference voltage terminal. Connected to a capacitor.
10 L.REF In Reference voltage terminal. Connected to a capacitor.
11 L.OUT Out Left channel sound waveform output
12 A.GND In Ground (0V) source for internal analog circuit
13 LRCK In Word clock (L/R separation signal) input.
14 LRSEL In Not used. Connected to ground.
15 SI In Sound data input
16 CLK In Bit clock input