SNC322

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 are two 4-bit I/O ports. Any bit of P2 and P3 can be

programmed as either input or output port individually. Any valid data transition (H

L

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

mode.

Input Port Configuration (P10~P13)

To Internal Data Bus

Read Control

PAD

Weak

Port Data

Port Status

To Internal Data Bus

Read Control

PAD

Weak

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

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

Ver: 1.2

December 26, 2002

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