STPCI2 STMicroelectronics, STPCI2 Datasheet - Page 86

• Manufacturer Part Number: STPCI2
• Description: STPC ATLAS DATASHEET - X86 CORE PC COMPATIBLE SYS
• Manufacturer: STMicroelectronics

DESIGN GUIDELINES
6.3.7. IDE / ISA DYNAMIC DEMULTIPLEXING
Some of the ISA bus signals are dynamically
multiplexed to optimize the pin count.
6.3.8. BASIC AUDIO USING IDE INTERFACE
When the application requires only basic audio
capabilities, an audio DAC on the IDE interface
can avoid using a PCI-based audio device. This
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Note * : the inverter can be removed when the DAC CS# is directly connected to GND
DD[15:0]
PCS1
PDIOW#
PDRQ
SYSRSTO#
Speaker
STPC
STPC bus / DD[15:0]
16
Vcc
Figure 6-13. Typical IDE / ISA Demultiplexing
D
RST
Vcc
PR
MASTER#
ISAOE#
LA[22]
LA[23]
LA[24]
LA[25]
Figure 6-14. Basic audio on IDE
Q
Q
*
Figure 6-13
74xx74
Issue 1.0 - July 24, 2002
DIR
OE
A
74xx245
D
RST
PR
Vcc
describes how to implement the external glue
logic to demultiplex the IDE and ISA interfaces. In
Local Bus mode the two buffers are not needed
and the NAND gates can be simplified to inverters.
low cost solution is not CPU consuming thanks to
the DMA controller implemented in the IDE
controller and can generate 16-bit stereo sound.
The clock speed is programmable when using the
speaker output.
B
Q
Q
D[15:0]
CS#
WR#
A/B
RMRTCCS#
KBCS#
RTCRW#
RTCDS
SA[19:8]
PCS1#
PCS3#
SCS1#
SCS3#
Stereo DAC
Right
Left
Audio Out