ML2254-XXXGA View Datasheet(PDF) - Oki Electric Industry

Part Name

Description

Manufacturer

ML2254-XXXGA

2-Channel Mixing Oki ADPCM Algorithm-Based Speech Synthesis LSI

Oki Electric Industry 

OKI Semiconductor

FEDL2250DIGEST-09

ML2250 family

Built-in ROM Usage Prohibited Area

(Applies to ML2251/52/53/54/56-XXX, ML22Q54/Q58)

The 8 bytes between the voice control area and the voice area in the ROM is the prohibited area for use.

The voice data are stored automatically behind 00808(HEX) address by using the development tool (AR207) when

creating the ROM data.

Table below lists the addresses prohibited for use in every ROM model.

Model

ML2251

ML2252

ML2253

ML2254, 22Q54

ML2256

ML22Q58

Voice data area

00808 to FFFF

00808 to 1FFFF

00808 to 5FFFF

00808 to 7FFFF

00808 to BFFFF

00808 to FFFFF

Usage prohibited area

00800 to 00807

00800 to 00807

00800 to 00807

00800 to 00807

00800 to 00807

00800 to 00807

Note: The addresses are indicated in hexadecimal notation.

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.

1.024 (Memory capacity – 16) (Kbit)

Playback time [sec] = Sampling frequency (kHz) Bit length

(Bit length is ADPCM, ADPCM 2 = 4 bits; PCM = 8 bits.)

Example: Let the sampling frequency is 16 kHz and 4-bit ADPCM algorithm. If one 8 Mbits ROM is used, then the

playback time is obtained as follows:

1.024 (8192 – 16) (Kbit)

Playback time =

16 (kHz) 4 (bit)

131 (sec)

The above equation gives the playback time when the phrase control table function is not used.

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