YMF744B Datasheet, PDF (18/60 Pages) List of Unclassifed Manufacturers – DS-1S

YMF744B
3Fh: Maximum Latency
Read Only
Default: 19h
Access Bus Width: 8, 16, 32-bit
b7 b6 b5 b4 b3 b2 b1 b0
Maximum Latency
b[7:0] ..........Maximum Latency
This register indicates how often DS-1S generates the Bus Master Request.
This register is hardwired to 19h.
40-41h: Legacy Audio Control
Read / Write
Default: 907Fh
Access Bus Width: 8, 16, 32-bit
b15 b14 b13 b12 b11 b10 b9 b8
LAD SIEN
MPUIRQ
SBIRQ
b7 b6
SDMA
b5 b4 b3 b2 b1 b0
I/O MIEN MEN GPEN FMEN SBEN
b0................SBEN: Sound Blaster Enable
This bit enables the mapping of the Sound Blaster Pro block in the I/O space specified by the SBIO bits,
when LAD is set to “0”. The FM Synthesizer registers can be accessed via SB I/O space, while the SB
block is enabled, even if FMEN is set to “0”.
“0”: Disable the mapping of the SB block to the I/O space
“1”: Enable the mapping of the SB block to the I/O space
(default)
b1................FMEN: FM Synthesizer Enable
This bit enables the mapping of the FM Synthesizer block in the I/O space specified by the FMIO bits,
when LAD is set to “0”. FM Synthesizer registers can be accessed via SB I/O space, while the SB block
is enabled, even if FMEN is set to “0”.
“0”: Disable the mapping of the FM Synthesizer block to the FMIO space
“1”: Enable the mapping of the FM Synthesizer block to the FMIO space (default)
After setting FMEN to “1”, about 100 msec is necessary before accessing these I/O space.
b2................GPEN: Gameport Enable
This bit enables the mapping of the Joystick block in the I/O space specified by the JSIO bits, when LAD
is set to “0”.
“0”: Disable the mapping of the Joystick block
“1”: Enable the mapping of the Joystick block
(default)
b3................MEN: MPU401 Enable
This bit enables the mapping of the MPU401 block in the I/O space specified by the MPUIO bits, when
LAD is set to “0”.
“0”: Disable the mapping of the MPU401 block
“1”: Enable the mapping of the MPU401 block
(default)
February 3, 1999
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