FEDL2280XFULL-04

ML22808/ML22804/Ml22802-XXX

Memory Allocation and Creating Voice Data

The ROM is partitioned into four data areas: voice (i.e., phrase) control area, test area, voice area, and edit ROM

area.

The voice control area manages the ROM’s voice data.

It contains data for controlling the start/stop addresses

of voice data for 256 phrases, use/non-use of the edit ROM function and so on.

The test area contains data for testing.

The voice area contains actual waveform data.

The edit ROM area contains data for effective use of voice data.

For the details, refer to the section of “Edit

ROM Function.”

No edit ROM area is available unless the edit ROM is used.

The ROM data is created using a dedicated tool.

ROM address (ML22808/ML22804/ML22802-XXX, ML22P808/ML22P804/ML22P802)

Voice control area

(Fixed16 Kbits)

Test area

Edit ROM area

Depends on creation

of ROM data.

0x00000

0x007FF

0x00800

Max: 0xFFFFF

Max: 0xFFFFF

0x00807

0x00808

Voice area

Playback Time and Memory Capacity

The playback time depends upon the memory capacity, sampling frequency, and playback method.

The equation showing the relationship is given below.

The equation below gives the playback time when the edit ROM function is not used.

(Bit length is 2 bits for 2-bit ADPCM2; 4 bits for 4-bit ADPCM2; 8 bits for PCM.)

Example

: Let the sampling frequency be 16 kHz and 4-bit ADPCM2 algorithm.

Then the playback time is

approx. 65 seconds, as shown below.

Playback time =

≅ 65 (sec)

1.

16

024

× (4096 – 16) (Kbit)

(kHz)

× 4 (bit)

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