Sound Generator Control Register - Fujitsu MB90390 Series Hardware Manual

CHAPTER 25 SOUND GENERATOR
25.2.1

Sound Generator Control Register

The sound control register controls the operation status of the sound generator by
controlling interrupts and setting the external output pins.
■ Sound Generator Control Register (Lower)
Figure 25.2-2 Configuration of the Sound Generator Control Register (Lower Byte)
bit 7
Address:
S1
00005E
H
R/W R/W R/W R/W
R/W :
:
536
6 5 4 3 2 1
S0 TONE OE2 OE1 INTE INT
R/W R/W R/W R/W
Readable and writable
Initial value
0
SGCR (lower)
ST
Initial value
0 0 0 0 0 0 0 0
B
bit 0
ST
0 Stop operation
1 Start operation
bit 1
INT
read
0 no interrupt
1 interrupt request
bit 2
INTE
0 Interrupt disabled
1 Interrupt enabled
bit 3
OE1
0 General purpose pin
1 SGA Output enabled
bit 4
OE2
0 General purpose pin
1 SGO Output enabled
bit 5
TONE
0 Tone and PWM mixed
1 SGO output
bit 7 bit 6
S1 S0
0 0
0 1
1 0
1 1
Start bit
Interrupt bit
write
clear interrupt
no effect
Interrupt enable bit
Amplitude output enable bit
Sound output enable bit
Tone output bit
Operation clock select bit
Machine clock
1/2 machine clock
1/4 machine clock
1/8 machine clock