CPU (LSI2: MSM6755B-17)
The CPU reads sound data from the ROM in accordance with the pressed key and the selected tone; the CPU
can read rhythm data simultaneously when a rhythm pattern is selected. Then it provides the left and the right
channelsO waveforms separately, by converting the data into the waveforms with two built-in DACs. The CPU
also controls key and button input. The following table shows the pin functions of LSI2.
Pin No.TerminalIn/OutFunction
1MA14OutAddress bus
2, 3NCONNot used
4 ~ 19MA0 ~ MA13OutAddress bus
13MRDBOutRead enable signal
17MCSBNNot used
20 ~ 27MD0 ~ MD7In/Out Data bus
28, 29NC1, NC2NNot used
30DGNDInGround (0 V) source
31DVCCIn+5 V source
32, 33XTLO, XTLIIn/Out 20 MHz clock input/output
34NC3NNot used
35RSTBInReset signal input
36P24/RXDInMIDI signal input
37P25/TXDOutMIDI signal output
38NMIInPower ON signal input. Connected to +5 V.
39APOOutAPO (Auto Power Off) signal output
40NC4NNot used
41REFHOutTerminal for the internal DAC
42, 43NC5, NC6NNot used
44DAOROutRight channel sound waveform output
45NC7NNot used
46AVdacIn+5 V source for the internal DAC
47DAOLOutLeft channel sound waveform output
48REFLOutTerminal for the internal DAC and ADC
49AGdacInGround source for internal DAC
50AGadcInGround source for internal ADC
51ANIInAPO cancellation signal
52AVadcIn+5 V source for the internal ADC
53NC8NNot used
54MOD0InMode selection terminal. Connected to +5 V.
55, 56MOD1, MOD2InMode selection terminal. Connected to ground.
57P40InPedal signal input
58 ~ 64KI0/P30 ~ KI7/P36InTerminals for key/button input signal
65KI7/P37NNot used
66 ~ 73KO0/P50 ~ KO7/P57OutTerminals for key scan signal
N 4 N |
ACEC
CASIO
