FEDL2201-01

1Semiconductor

ML2201–XXX

10/20

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;

Playback Time (sec) =

=

For example, when you store all phrases at 8.0 kHz Sampling Frequency, the maximum playback time is

calculated as follows;

Playback Time (sec) =

≅ 6.0 sec

Playback Algorithm

ML2201 uses

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 f

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

32 ms

Maximum Time length of Silence

992 ms

Incremental Step

32 ms

Memory Size (Bit)

Bit Rate (bps)

Memory Size (Bit)

Ext. Clock Frequency (Hz)

× 8

(384 – 6)

× 1024 Bit

8000 (Hz)

× 8 Bit