CASIO WK1500
Service Manual

DAC (IC11: UPD6376GS)
The DAC receives 16-bit serial data output from the DSP. The data contains digital sound data of the melody, chord, bass, and percussion for the right and left channels. The DAC converts the data into analog waveforms by each channel and output them separately. The following table shows the pin functions of IC11.

Pin No. 1 2 3 4 5 6 7, 8 9 10 11 12 13 14 15 16

Terminal SEL D.GND NC DVDD A.GND R.OUT A.VDD R.REF L.REF L.OUT A.GND LRCK LRSEL SI CLK

In/Out In In � In In

Function Mode selection terminal. Connected to ground. Ground (0 V) source for the internal digit circuit Not used. +5 V source for the internal digital circuit Ground (0 V) source for the right channel Right channel sound waveform output +5 V source for the internal analog circuit Right channel reference voltage terminal Left channel reference voltage terminal Left channel sound waveform output Ground (0 V) source for the left channel Word clock input Not used. Connected to ground. Sound data input Bit clock input

KEY CONTROLLER (LSI16: HG52E35P)
The key controller generates key scan signals and provides them to the keyboard. By counting the time between first-key input signal FI and second-key SI from the keyboard, the key controller detects key velocity. The note number and its velocity data are read at regular intervals by the CPU.

RDAB LSI17 HG52E35P WRAB CLKA HGB

Key Controller LSI16 HG52E35P CRDB CWRB CKI CCSB RESB CD0 KC0 KC7 Key scan signal

~

Out In In In

Out In In In In In

Keyboard

KC

~

RESET Data bus

First contact FI0 SI0 Key input signal FI9 SI9 FI SI Second contact

CD7 Address bus CA0 ~ CA2

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