YMF744B
February 3, 1999
-15-
14-17h: Legacy Audio I/O Base Address (Dummy for SB, FM, MPU, D-DMA)
Read / Write
Default: 00000001h
Access Bus Width: 8, 16, 32-bit
b15
b14
b13
b12
b11
b10
b9
b8
b7
b6
b5
b4
b3
b2
b1
b0
IOBASE0
-
-
-
-
-
I/O
b31
b30
b29
b28
b27
b26
b25
b24
b23
b22
b21
b20
b19
b18
b17
b16
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
b0................IO
(Read Only)
This bit indicates that the base address is assigned to I/O. This bit is hardwired to “1”.
b[15:6] ........IOBASE0
This register is used so that the OS may secure I/O resources for Sound Blaster Pro, FM Synthesizer,
MPU401 and D-DMA controller. Because this register is a dummy one, each for the I/O addresses of
the above blocks is assigned with the I/O addresses set to 4C-4Dh and 60-65h respectively by the software
driver.
18-1Bh: Legacy Audio I/O Base Address (Dummy for Joystick)
Read / Write
Default: 00000001h
Access Bus Width: 8, 16, 32-bit
b15
B14
b13
b12
b11
b10
b9
b8
b7
b6
b5
b4
b3
b2
b1
b0
IOBASE1
-
I/O
b31
B30
b29
b28
b27
b26
b25
b24
b23
b22
b21
b20
b19
b18
b17
b16
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
b0................IO
(Read Only)
This bit indicates that the base address is assigned to I/O. This bit is hardwired to “1”.
b[15:2] ........IOBASE1
This register is used so that the OS may secure I/O resource for the joystick port. Because this register is
a dummy one, the joystick I/O address is assigned with the I/O address set to 66-67h by the software
driver.