CY7C65640A
Introduction
Cypress’s TetraHub™ is a high-performance self-powered
Universal Serial Bus (USB) 2.0 hub. The Tetra architecture
provides four downstream USB ports, with a Transaction
Translator (TT) for each port, making it the highest-perfor-
mance hub possible. This single-chip device incorporates one
upstream and four downstream USB transceivers, a Serial
Interface Engine (SIE), USB Hub Controller and Repeater, and
four TTs. It is suitable for standalone hubs, motherboard hubs,
and monitor hub applications.
Being a fixed-function USB device, there is no risk or added
engineering effort required for firmware development. The
developer does not need to write any firmware for their design.
The CY4602 Tetrahub USB 2.0 4-port Hub Reference Design
Kit provides all materials and documents needed to move
rapidly into production. The reference design kit includes
board schematics, bill of materials, Gerber files, Orcad files,
key application notes, and product description.
CY7C65640A-LFXC is a functional and pin equivalent die
revision of Cypress's CY7C65640-LFXC. Changes were
made to improve device performance.
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Verify and select DATA toggle values
Port power control and over-current detection.
The Hub Controller provides status and control and permits
host access to the hub.
Hub Repeater
The Hub Repeater manages the connectivity between
upstream and downstream facing ports that are operating at
the same speed. It supports full-/low-speed connectivity and
high speed connectivity. Per the USB 2.0 specification, the
Hub Repeater provides the following functions:
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Sets up and tears down connectivity on packet boundaries
Ensures orderly entry into and out of the Suspend state,
including proper handling of remote wakeups.
Transaction Translator
The TT basically translates data from one speed to another. A
TT takes high speed split transactions and translates them to
full-/low-speed transactions when the hub is operating at high
speed (the upstream port is connected to a high speed host
controller) and has full-/low-speed devices attached. The
operating speed of a device attached on a downstream facing
port determines whether the Routing Logic connects a port to
the Transaction Translator or Hub Repeater section. If a low or
full speed device is connected to the hub operating at high
speed, the data transfer route includes the transaction trans-
lator. If a high speed device is connected to this high speed
hub the route only includes the repeater and no transaction
translator since the device and the hub are in conformation
with respect to their data transfer speed. When the hub is
operating at full speed (the upstream port is connected to a full
speed host controller), a high speed peripheral will not operate
at its full capability. These devices will only work at 1.1 speed.
Full- and low-speed devices connected to this hub will operate
at their 1.1 speed.
TetraHub Architecture
The
tecture.
USB Serial Interface Engine (SIE)
The SIE allows the CY7C65640A to communicate with the
USB host through the USB repeater component of the hub.
The SIE handles the following USB bus activity independently
of the Hub Control Block:
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Bit stuffing/unstuffing
Checksum generation/checking
ACK/NAK/STALL
TOKEN type identification
Address checking.
Applications
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Standalone Hubs
Motherboard Hubs
Monitor Hub applications
External Personal Storage Drives
Port Replicators
Portable Drive
Docking Stations
Hub Controller
The Hub Control Block does the following protocol handling at
a higher level:
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Coordinate enumeration by responding to SETUP packets
Fill and empty the FIFOs
Suspend/Resume coordination
Document #: 38-08019 Rev. *J
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