MSM9802 View Datasheet(PDF) - Oki Electric Industry

Part Name

Description

Manufacturer

MSM9802

Voice Synthesis IC with Built-in Mask ROM

Oki Electric Industry 

¡ Semiconductor

MSM9802/03/05-xxx

If playback is attempted at an unused address in the phrases, AOUT goes to 1/2 IAOUT and

playback does not occur. Figure 3.2 shows the timing.

A2-A0 (I)

SW2-SW1 (I) "L"

SW0 (I)

BUSY (O)

AOUT (O)

Oscillation start

Figure 3.2 Timing when Playback is Attempted at an Unused Phrase Address

In the SW input interface, no phrase is triggered when SW2 to SW0 are all set to "0". Therefore,

when the circuit consists of a diode matrices that use push-button switches, the maximum

playback phrases are 56 phrases.

A2-A0

000

001

002

SW2-SW0

(000)

Code Prohibited

001

¥ 002 = 56 Phrases

111

111

8 codes ¥ 7 codes = 56

3.2 Random playback function

The random playback function randomly generates 15 different addresses corresponding to the

four bits of the addresses of A0 and SW2-SW0 (except ALL "L") on the IC, after which playback

commences.

Therefore, any input to A0 and SW2 to SW0 pins from external control is invalid. Hold these 4

pins either "H" or "L" level. SW2 to SW0 pins may be held open as they have internal pull-down

resistor.

Playback may not occur if all the 15 addresses have not been assigned a phrase. Care must be

taken when creating ROM data.

For example, when four phrases, "sunny", "rainy", "cloudy", and "snowy", are to be played

randomly, set the phrases as shown in Table 3.1 in which a phrase is assigned to all the 15

addresses. The four phrases are then played back at random as shown below.

15/51

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