cs5535 National Semiconductor Corporation, cs5535 Datasheet - Page 36

• Manufacturer Part Number: cs5535
• Description: Geode Cs5535 Companion Multi-function South Bridge
• Manufacturer: National Semiconductor Corporation

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Signal Definitions
2.2.3.1
Signal Name
IDE_IOR0#
IDE_IOW0#
IDE_CS0#
IDE_CS1#
IDE_DREQ0
IDE_DACK0#
IDE_RDY0
IDE Interface Signals (Continued)
Ball No.
(Continued)
B13
C13
B10
C10
C12
A14
A13
Type
O
O
O
O
O
I
I
Description
IDE I/O Read. This output is asserted on read accesses to corre-
sponding IDE port addresses.
When in Ultra DMA/33 mode, this signal is redefined:
• IDE_HDMA_RDY - Host DMA Ready for Ultra DMA data-in bursts
• IDE_HDMA_DS - Host DMA Data Strobe for Ultra DMA data-out
IDE I/O Write. This output is asserted on write accesses to corre-
sponding IDE port addresses.
When in Ultra DMA/33 mode, this signal is redefined:
• IDE_STOP - Stop Ultra DMA data burst
IDE Chip Select 0. This chip select signal is used to select the Com-
mand Block registers in IDE Device 0.
IDE Chip Select. This chip select signal is used to select the Com-
mand Block registers in IDE Device 1.
DMA Request. The DREQ input is used to request a DMA transfer
from the CS5535. The direction of the transfers are determined by the
IDE_IOR0# and IDE_IOW0# signals.
Note:
DMA Acknowledge. The DACK# output acknowledges the
IDE_DREQ0 request to initiate DMA transfers.
I/O Ready. When de-asserted, this signal extends the transfer cycle
of any host register access when the device is not ready to respond to
the data transfer request.
When in Ultra DMA/33 mode, this signal is redefined:
• IDE_DDMA_DS - Device DMA Data Strobe for Ultra DMA data-in
• IDE_DDMA_RDY - Device DMA Ready for Ultra DMA data-out
bursts
bursts
bursts
Ball A14 is the only ball that changes direction from IDE to
Flash (input when in IDE mode, output when in Flash mode).
If this interface is to be switched between IDE and Flash
modes, then ball A14 needs an external pull-up to keep it high
during IDE mode.
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Revision 0.8