Disk Drive Operation
WA31273A / WA32543A / WA33203A / WA32163A / WA31083A / WA32162A5-7
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Programmable IRQ timer to allow automation to work with different BIOS implementations and
different device drivers.
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IORDY for PIO flow control.
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40-byte host FIFO to allow automation to occur smoothly during discontinuities in transfers on the
ATA interface.
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Auto Command support.
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Automation of an extensive portion of the ATA command set.
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LBA or CHS Task File Modes.
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Provides logic for daisy chaingin two embedded disk controllers.
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On-chip 12mA Host Drivers.
The SID-9501D also supports a basic ATAPI environment. this consists of:
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ATAPI Reset command.
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ATAPI Packet command.
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ATAPI Identify Device commands.
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ATAPI Service command.
The SID-9501D supports both PIO and DMA type transfers. The supported DMA type transfers includes
single-word, multi-word, and synchronous DMA transfers. DMA transfers and PIO transfers utilize the bus in
8- or 16-bit mode depending upon the command being executed. The bus is automatically switched between
16- and 8-bit mode while performing Read Long and Write Long commands at the time of ECC byte transfers.
Additional functionality is provided in the Host Interface block by the following features:
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Programmable transfer length for automatic ECC byte transfer on the AT bus.
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Automatically inserted wait states are provided to support the IOCHRDY signal pin functions at
any ATA interface speed.
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Support for Master/Slave configuration of two embedded disk controller drives.
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Automatic detection of Host status reads.
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Support of both LBA and CHS Task File register formats.
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Automatic detection of both the software AT reset and hardware AT reset.
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12-mA drivers are provided for direct connection to the ISA/EISA bus. Some ATA inputs are
Schmitt trigger inputs.
