CY7C68023/CY7C68024
Document #: 38-08055 Rev. *C
Page 5 of 10
Applications
The NX2LP is a high speed USB 2.0 peripheral device that
connects NAND Flash devices to a USB host using the USB
Mass Storage Class protocol.
Additional Resources
■ CY3685 EZ-USB NX2LP Development Kit
■ CY4618 EZ-USB NX2LP Reference Design Kit
■ USB Specification version 2.0
■ USB Mass Storage Class Bulk Only Transport Specification,
http://www.usb.org/devel-
opers/devclass_docs/usbmassbulk_10.pdf .
Functional Overview
USB Signaling Speed
The NX2LP operates at two of the three rates defined in the USB
Specification Revision 2.0 dated April 27, 2000:
■ Full speed, with a signaling bit rate of 12 Mbits/sec
■ High speed, with a signaling bit rate of 480 Mbits/sec.
The NX2LP does not support the low speed signaling rate of
1.5 Mbits/sec.
NAND Flash Interface
During normal operation the NX2LP supports an 8-bit I/O
interface, eight chip enable pins, and other control signals
compatible with industry standard NAND Flash devices.
Enumeration
During the startup sequence, internal logic checks for the
presence of NAND Flash with valid configuration data in the
configuration data memory area. If valid configuration data is
found, the NX2LP uses the values stored in NAND Flash to
configure the USB descriptors for normal operation as a USB
mass storage device. If no NAND Flash is detected, or if no valid
configuration data is found in the configuration data memory
area, the NX2LP uses the default values from internal ROM
space for manufacturing mode operation. The two modes of
operation are described in the following sections.
Normal Operation Mode
In Normal Operation Mode, the NX2LP behaves as a USB 2.0
Mass Storage Class NAND Flash controller. This includes all
typical USB device states (powered, configured, and so on). The
USB descriptors are returned according to the data stored in the
configuration data memory area. Normal read and write access
to the NAND Flash is available in this mode.
Manufacturing Mode
In Manufacturing mode, the NX2LP enumerates using the
default descriptors and configuration data that are stored in
internal ROM. This mode enables first-time programming of the
configuration data memory area, and board-level manufacturing
tests.
A unique USB serial number is required for each device in order
to comply with the USB Mass Storage specification. Cypress
also requires designers to use their own Vendor ID for final
products. The Vendor ID is obtained through registration with the
USB Implementor’s Forum (USB-IF), and the Product ID is deter-
mined by the designer.
Cypress provides all the software tools and drivers necessary for
properly programming and testing the NX2LP. Refer to the
documentation in the development or reference design kit for
more information on these topics.
Figure 3. NX2LP Enumeration Process
NAND Flash
Programmed?
Load Default
Descriptors and
Configuration Data
Manufacturing
Mode
Load Custom
Descriptors and
Configuration Data
Enumerate As
USB Mass
Storage Device
Normal Operation
Mode
Start-up
Enumerate As
Generic NX2LP
Device
NAND Flash
Present?
No
Yes
Yes
No
[+] Feedback
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
