Casio CTK-750 manual Key Touch LSI HG52E35P

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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.

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

 

 

 

 

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.

Keyboard

KC

First contact

Key scan signal

Key touch LSI

HG52E35P

KC0 RESB

CCSB

KC7 CWRB CRDB CKI

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

FI

SI

Second contact

Key input signal

FI0

SI0

FI7

CD0

CD7

Data bus

SI7 CA0 ~ CA2

Address bus

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Image 12
Contents CTK-750 Contents Specifications GeneralReplacing the DSP HG51A115A01FD ElectricalBlock Diagram UPD6376CXCircuit Description Key MatrixReset Circuit Nomenclature of KeysButton Matrix MidiCPU HD6433298A18P Pin No Terminal In/Out FunctionGate Array UPD65005C-578 Digital Signal Processor HG51A115A01FD Block diagram of DSP and DAC circuit Key Touch LSI HG52E35P Filter Block Power Amplifier LA4620 Power Supply CircuitName Voltage For operation AvddWiring Diagram M5712-CN1MMajor Waveforms Page PCB View and Major Check Points Schematic Diagrams Console PCB M5712-CN1M Keyboard PCBs M615T-KY1M, KY2M Exploded View IC Lead Identification and Internal Diagram S8053ANOM5218APR PC900VQ2 2SD1762E,F Q4 2SB1274 EB C EBe C B Parts List N N FOB Japan Code No Parts Name Specification Yen Unit Price Lower Case Screws MA0300941A