Casio GZ-500 manual Digital Signal Processor LSI102 HG51B155FD, Pin No Terminal In/Out Function

CPU (LSI106: HD6433298A42F)

The 16-bit CPU contains a 32k-bit ROM, a 1k-bit RAM, seven 8-bit I/O ports, an A/D convertor and MIDIl interfaces. The CPU accesses to the working storage RAM, the DSP and the key touch LSI. The CPU interprets MIDI message using the working storage RAM. The CPU also controls buttons and LEDs. The following table shows the pin functions of LSI106.

Pin No.	Terminal	In/Out			Function
1	P50/TXD		Out		MIDI signal output
2	P51/RXD			In	MIDI signal input
3	P52/SCK		Out		Reset signal output
4	-RESET			In	Reset signal input
5	-NMI			In	Power ON trigger signal input
6	VCC			In	+5V source
7	-STBY			In	Standby signal input. Connected to +5V.
8	VSS			In	Ground (0V) source
9, 10	XTAL, EXTAL			In	20MHz clock input
11, 12	MD1, MD0			In	Mode selection input
13	AVSS			In	Ground (0V) source
14	P70			In	Analog input terminal for the pitch bend wheel
15	P71			In	APO cancellation signal input
16	P72				Not used. Connected to +5 V source.
17 ~ 21	P73 ~ P77		Out		LED drive signal output
22	AVCC			In	+5V source
23 ~ 30	P60 ~ P67		Out		LED drive signal output
31	VCC			In	+5V source
32	P27				Not used
33 ~ 48	A0 ~ A14		Out		Address bus
40	VSS			In	Ground (0V) source
49 ~ 56	D0 ~ D7	In/Out			Data bus
57	P40		Out		Clock for KO signal generator
58	P41		Out		KO signal data
59	P42		Out		APO signal output
60	P43		Out		Read enable signal output
61	P44			In	Write enable signal output
62	P45				Not used
63	P46		Out		10 MHz clock output
64	P47				Not used. Connected to +5 V source.

DIGITAL SIGNAL PROCESSOR (LSI102: HG51B155FD)

Upon receipt of note numbers and their velocities, the DSP reads sound and velocity data from the sound source ROM in accordance with the selected tone; the DSP can read rhythm data simultaneously when a rythm pattern is selected. Then it provides 16-bit serial signal containing data of the melody, chord, bass, and percussion to the DAC. When an effect selected, the DSP adds the effect to the sound data using a 256k-bit RAM.

The following table shows the pin functions of LSI102.

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