ml22460mb Oki Semiconductor, ml22460mb Datasheet - Page 17

• Manufacturer Part Number: ml22460mb
• Description: Speech Synthesis Lsi With Serial Rom Interface Including 4-channel Mixing Function
• Manufacturer: Oki Semiconductor

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 voice data in the ROM. It contains data for controlling the start/stop
addresses of voice data for 1,024 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.”
The edit ROM area is not available if the edit ROM is not used.
The ROM data is created using a dedicated tool.
Playback Time and Memory Capacity
The playback time depends on the memory capacity, sampling frequency, and playback method.
The equation to know the playback time is shown below. But this is not applied if the edit ROM function is
used.
Configuration of ROM data
Playback time [sec] =
Playback time =
(Bit length is 4 at the 4-bit ADPCM2 and 8/16 at the PCM.)
Example) In the case that the sampling frequency is 16 kHz, algorithm is 4-bit ADPCM2 and ROM capacity
max: 0xFFFFFF
max: 0xFFFFFF
0x01FFF
0x00000
0x02000
0x0205F
0x02060
is 16 Mbits, the playback time is approx. 261 seconds, as shown below.
(16,000 x 1.024 – 64) x 1.024
Depends on creation
(Memory capacity – 64) [Kbit] x 1.024
Sampling frequency [kHz] × Bit length
Voice control area
(Fixed 64 Kbits)
Edit ROM area
of ROM data.
Test area
16 × 4
Voice area
≅ 261 [sec]
ML22420MB/ ML22460MB
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