Specifications

I-100 EPSON S1C62N82 TECHNICAL HARDWARE

CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Melody Generator)

Playing mode

The S1C62N82 Series have 3 modes for melody playing: one

shot mode, level hold mode and retrigger mode. The control

of these modes is done through operation of the MELC

(a)One shot mode

In this mode, only one specified melody is played; playing

automatically stops when the melody ends. Control

procedures are as follows:

(1)Set the melody ROM address (start address) of the

desired melody in the address register (MAD0–MAD6).

(2)Immediately after writing "1" (before the melody play-

ing ends), write "0" on the MELC register.

The above operation will allow only one melody to be

played. Melody playing is started from the address

written on the address register, by writing "1" on the

MELC register. When playing of the last word of a

melody (end- of-melody data is "1") ends, end-of-melody

signal is generated and interrupt request to the CPU and

interrupt flag are generated in the melody interrupt

generator. At this point, since "0" has previously been

written on the MELC register with the above operation

(2), signal to halt playing is generated in the controller

and hence, playing will stop.

The relationship between MELC register value and play-

ing output is shown in Figure 4.11.17.

Fig. 4.11.17

One shot mode

100

Approx. 125 ms

Generation of

melody interrupt

PlayingPlaying

"MELC"