SNC104

One Channel Direct Drive Speech Controller

5 FUNCTION DESCRIPTIONS

5.1. Oscillator

SNC104 accepts RC type oscillator for system clock. The typical circuit diagram for

oscillator is listed as follows.

OSC

VCC

RC Oscillator

5.2. ROM

SNC104 contains substantial 64K word (10-bit) internal ROM. Program, voices and

other data are shared with this same 64K word ROM.

5.3. RAM

SNC104 contains 64 nibble RAM. The 64 nibble RAM is divided into four pages (page

0 to page 3, 16 nibble RAM on each page). In our programming structure, users can

easily define and locate RAM page in the program. For instance, users can use the

instructions, PAGEn (n=0 to 3) to switch and indicate the RAM page. Besides, users

can use direct mode, M0 ~ M15 in the data transfer type instructions, to access all 16

5.4. Power Down Mode

“End” instruction will power down SNC104 and enable IC to consume fewer current for

power saving. (<3uA @VDD=3V and <5uA @VDD=5V) Please be aware that when

the power down mode is activated in SNC104, any valid data transition (L H or H L)

occurring on any input port (P1) or IO ports (P2 and P3) will lead SNC104 back to

normal operation mode.

5.5. Sampling Rate Counter

The unique sampling rate counter is designed in voice channel to be able to play

diverse voices at different sample playing rates. The playing rate can be adaptively

set up among from the wide ranges of 2.5KHz to 20KHz. This feature makes voice

close to its original source and yield the better voice quality.

Ver: 1.0

October 23, 2002

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