CY7C68300C/CY7C68301C
CY7C68320C/CY7C68321C
Figure 8. SYSIRQ Latching Algorithm
No
USB Interrupt
Pipe Polled?
Yes
Int_Data = 1?
No
NAK Request
Yes
Return Interrupt Data
Set Int_Data = 0
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| No |
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| SYSIRQ=1? | ||||
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| Yes |
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| Latch State of IO Pins | ||||
Yes |
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| Set Int_Data = 1 | ||||||
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No
Int_Data = 0
and
SYSIRQ=0?
DRVPWRVLD
When this pin is enabled with bit 0 of configuration address 0x08 (DRVPWRVLD Enable), the AT2LP informs the host that a removable device, such as a CF card, is present. The AT2LP uses DRVPWRVLD to detect that the removable device is present. Pin polarity is controlled by bit 1 of configuration address 0x08. When DRVPWRVLD is deasserted, the AT2LP reports a “no media present” status (ASC = 0x3A, ASQ = 0x00) when queried by the host. When the media has been detected again, the AT2LP reports a “media changed” status to the host (ASC = 0x28, ASQ = 0x00) when queried.
When a removable device is used, it is always considered by the AT2LP to be the IDE master device. Only one removable device may be attached to the AT2LP. If the system only contains a removable device, bit 6 of configuration address 0x08 (Search ATA Bus) must be set to ‘0’ to disable ATA device detection at startup. If a
GPIO Pins
The GPIO pins allow for a general purpose input and output interface. There are several different interfaces to the GPIO pins:
•Configuration bytes 0x09 and 0x0A contain the default settings for the GPIO pins upon initial AT2LP configuration.
•The host can modify the settings of the GPIO pins during operation. This is done with
•The status of the GPIO pins is returned on the interrupt endpoint (EP1) in response to a SYSIRQ. See “SYSIRQ” on page 12 for SYSIRQ details.
LOWPWR#
LOWPWR# is an output pin that is driven to ‘0’ when the AT2LP is not in suspend. LOWPWR# is placed in
ATA Interface Pins
The ATA Interface pins must be connected to the corre- sponding pins on an IDE connector or mass storage device. To allow sharing of the IDE bus with other master devices, the AT2LP can place all ATA Interface Pins in a
Design practices for signal integrity as outlined in the
Document | Page 13 of 42 |
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