CY7C68310 CYPRESS [Cypress Semiconductor], CY7C68310 Datasheet - Page 13

• Manufacturer Part Number: CY7C68310
• Manufacturer: CYPRESS [Cypress Semiconductor]

Table 6-1. CY7C68310 Configuration and USB Descriptor Sources
6.1.1
The CY7C68310 provides support for the 24LCXXB family of
EEPROMs.
CY7C68310 waits 50 ms and then checks for I
device presence. If an I
does not pass signature check, the CY7C68310 re-tests the
signature with each vendor-specific USB load or read access
of configuration bytes 0 and 1. Once the signature check
passes, I
requests. If an I
always assumed present until the next reset cycle (nRESET).
If an I
response when required causes the CY7C68310 to stall that
USB request. The CY7C68310 will attempt the access again
with the next USB request.
6.1.2
Configuration and descriptor data can also be supplied by an
attached mass storage device (IMODE) through a vendor-
specific Identify (FBh) ATA command. The CY7C68310
provides 256 bytes of internal RAM for FBh data storage.
Unlike operation with an external I
device, IMODE operation requires the attached device first be
initialized and FBh data retrieved before the CY7C68310 can
allow USB enumeration. To meet USB specification require-
ments, IMODE operation must be limited to systems that draw
100 mA or less from VBUS prior to USB configuration.
Document 38-08030 Rev. *H
SDA_nIMODE = 0
2
C-compatible device is present, a lack of an ACK
Yes
Yes
No
No
No
I
IMODE
2
2
C-compatible data is returned for USB descriptor
C-compatible Device
Following
2
C-compatible device is detected initially, it is
Device Present
I
2
C-compatible
2
C-compatible device is present but
the
N/A
N/A
Yes
Yes
No
release
2
C-compatible memory
Check Passes CY7C68310 Configuration and USB Descriptor Retrieval Method
I
2
of
C Signature
N/A
Yes
Yes
No
No
nRESET,
2
C-compatible
In this mode, the CY7C68310 uses internal ROM contents for USB
descriptor information and configuration register values. This mode is
for debug/manufacturing operation only. Not for shipping products.
In this mode, the CY7C68310 uses internal ROM contents for USB
descriptor information. Configuration register values are loaded from
internal ROM. This is not a valid mode of operation.
The CY7C68310 retrieves all Descriptor and Configuration values from
the vendor-specific Identify (FBh) data. The CY7C68310 is configured
using internal ROM values until FBh data becomes available.
The CY7C68310 uses internal ROM contents for USB descriptor infor-
mation. Configuration register values are loaded from internal ROM. In
this mode of operation, any CY7C68310 vendor-specific configuration
access causes the CY7C68310 to recheck the signature field. Once
the signature check passes, SROM data is returned for USB
descriptors requests. This is not a valid mode of operation.
The CY7C68310 retrieves all Descriptor and Configuration values from
the I
using these values.
the
2
C-compatible memory device. The CY7C68310 is configured
6.1.3
The CY7C68310 also contains an internal set of CY7C68310
configuration and USB descriptors. The internal descriptors
may only be used during manufacturing, as the internal ROM
values disable some features required for normal operation to
aid use in a manufacturing environment. Also, the internal
ROM descriptors do not provide a unique serial number
(required for USB Mass Storage Class compliance), and
therefore cannot be used for shipping products. See Table 6-
2 for the organization of the internal ROM contents. An
external I
vendor-specific FBh identify command is required to correctly
configure the CY7C68310 for operation and provide a unique
serial number for MSC compliance.
6.2
CY7C68310 configuration and USB descriptor data can be
supplied from an I
CY7C68310 can address 2 Kbytes of I
CY7C68310 configuration and USB descriptor information are
limited to 512 bytes maximum. Unused register space in the
I
specific data storage. Note that no descriptor is allowed to
span multiple pages within the I
device.
2
C-compatible serial memory device may be used for product
Internal ROM Contents
EEPROM Organization
2
C-compatible memory device or utilization of the
2
C-compatible serial memory device. The
2
C-compatible serial memory
2
C-compatible data, but
CY7C68310
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