YMF795

-18-

$33h Clock selection

Default: 0000h

Index

b15

b14

b13

b12

b11

b10

b9

b8

b7

b6

b5

b4

b3

b2

b1

b0

$33h

0

0

0

0

0

0

0

0

0

0

0

0

0

CLKSEL

This register is used to set the clock frequency inputted through CLK_I pin when making the clock setting in the

preset mode.

A clock with any frequency can be input during the reset period.

(For details of the clock setting, see “On clock frequency setting” (page 24)).

CKSEL [2:0]

Clock frequency (MHz)

0h(*)

2.688

1h

19.200

2h

19.680

3h

19.800

4h

8.400

5h

14.400

6h

27.821

7h

12.600

(*)When clock is set in the programmable mode, set CLKSEL[2:0] to “0h”.

$34h Interrupt control

Default: 0000h

Index

b15

b14

b13

b12

b11

b10

b9

b8

b7

b6

b5

b4

b3

b2

b1

b0

$34h

0

0

0

0

0

0

0

0

0

0

IRQE

IRQ point

The musical score data is taken into the FIFO which has a capacity for 32 data. As the sounds are reproduced, the data in

FIFO are processed and deleted. And when the amount of data remaining in FIFO becomes less than the setting value of

IRQ point, an interrupt signal is generated. At this point, set “0” to IRQE and then write the subsequent musical score

data into FIFO.

Be sure to write data in excess of the IRQ point. After writing the data, reset IRQE to “1” and wait another interrupt

signal.

IRQ point can be set in 32 ways from 0 (empty) to 31 (1 data vacancy).

IRQE is the interrupt enable bit. “1” indicates Enable.