SNC375

Direct Drive Voice/Dual Tone Melody Controller

5.6. Dual-Tone Generator

A dual-tone melody generator is included to generate 2-channel music songs with a

pleasant square-wave-like timbre. The pitch range of each tone generator is as wide

as 4 octaves (48 different notes totally). The output of dual-tone generator can be

mixed with the output of voice synthesizer to achieve voice playing with BGM

(background music).

Additionally, Sonix provides a numbered-musical-notation

representation to help users compose their songs. Further, a MIDI (1.0) file translator

can convert MIDI files into Sonix format.

5.7. I/O Ports

P1 is a 4-bit input port and P2/P3/P6 are three 4-bit I/O ports. Any bit of P2, P3 and P6

can be programmed as either input or output port individually. Any valid data transition

(H

L or L H) of P1, P2, P3 and P6 can reactivate the chip when the chip is in

power-down mode.

To Internal Data Bus

Read Control

PAD

Weak

Input Port Configuration (P10~P13)

Port Data

Port Status

To Internal Data Bus

Read Control

PAD

Weak

I/O Port Configuration (P20~P23, P30~P33, P60~P63)

Note: weak N-MOS’s can serve as pull-low resistor.

Ver: 1.4

June 8, 2005

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