FEDL2201-02
OKI Semiconductor
ML2201-XXX
You can calculate playback time length with memory size divided by a bit rate. The following formula can be used
for 8-bit PCM-based ML2201;
Memory Size (Bit)
Ext. Clock Frequency (Hz) × 8
Memory Size (Bit)
Bit Rate (bps)
Playback Time (sec) =
=
For example, when you store all phrases at 8.0 kHz Sampling Frequency, the maximum playback time is
calculated as follows;
(384 – 6) × 1024 Bit
8000 (Hz) × 8 Bit
Playback Time (sec) =
≅ 6.0 sec
Playback Algorithm
ML2201 uses OKI Non-Linear PCM algorithm, an advanced variation of PCM.
In mid-range wave-form, this algorithm has precision and quality equivalent to those of 10-bit Straight PCM.
Inserting Silence
In addition to playing normal recorded sound phrases, ML2201 allows you to insert silence (a silent phrase) . You
can define time length of silence freely in 32 ms steps, within the range of minimum 32 ms and maximum 992 ms
at fOSC = 4.096 MHz. Those time length vary in proportion to the oscillation frequency, fOSC
.
Phrase Control Table
The user-definable on-chip Phrase Control Table feature enables you to play back multiple phrases in a single
continuous session with just the same simple control as in a regular single phrase playback. You can assign up to 8
phrases including a silent phrase (s) to a single address. This allows you to get the most out of limited memory
space because you can eliminate duplicate sound data.
As an example, let’s assume you want to create several similar phrases like “It will be xxxxx today”. “xxxxx” can
be “sunny”, “rainy” or “cloudy”. The common words such as “It”, “will be” and “today” are created separately as
an independent phrase, and phrasing order information is stored in the Phrase Control Table, as shown in the Table
2 and Figure 2.1. From the external control, simply selecting an X address causes the LSI to play multiple phrases
continuously. In this example shown in the Table 2, selecting [01] address starts to play “It will be fine today,
while selecting [02] “It will be rainy today”.
You can also insert a silent phrase to the Phrase Control Table without consuming any memory space.
Minimum Time Length of Silence
Maximum Time length of Silence
Incremental Step
32 ms
992 ms
32 ms
10/22
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