SNC205

Direct Drive Speech Controller

5. FUNCTION DESCRIPTIONS

5.1. Oscillator

SNC205 accept RC type oscillator for system clock. The typical circuit diagram for

oscillator is listed as follow.

OSC

VCC

RC Oscillator

5.2. ROM

SNC205 contains substantial 52K words (10-bit) internal ROM. Program, voices and

other data are shared with this same 52K words ROM.

5.3. RAM

SNC205 contains 32 nibbles RAM. The 32 nibbles RAM are divided into two pages

(page 0 and page 1, 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 1) 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 nibbles of each page.

5.4. Power Down Mode

“End” instruction will power down SNC205 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 SNC205, any valid data transition (L H or H L)

occurring on any IO pins of P3 will lead SNC205 back to normal operation mode.

5.5. Sampling Rate Counters

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: 1.1

June 8, 2005

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