CY7C65640A-LFC Cypress Semiconductor Corp, CY7C65640A-LFC Datasheet - Page 4

• Manufacturer Part Number: CY7C65640A-LFC
• Manufacturer: Cypress Semiconductor Corp

Specifications of CY7C65640A-LFC

• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (min): 3.15V
• Operating Supply Voltage (max): 3.45V
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 56
• Lead Free Status / RoHS Status: Not Compliant

Functional Overview
The Cypress TetraHub USB 2.0 hub is a high performance,
low-system-cost solution for USB. This hub integrates 1.5k
upstream pull up resistors for full speed operation and all
downstream 15k pull down resistors and series termination
resistors on all upstream and downstream D+ and D– pins. This
results in optimization of system costs by providing built-in
support for the USB 2.0 specification.
System Initialization
On power up, the TetraHub reads an external SPI EEPROM for
configuration information. At the most basic level, this EEPROM
has the Vendor ID (VID), Product ID (PID), and Device ID (DID)
for the customer's application. For more specialized applica-
tions, other configuration options can be specified. See
uration Options
After reading the EEPROM, if BUSPOWER (connected to the
upstream VBus) is high, TetraHub enables the pull up resistor on
the D+ to indicate that it is connected to the upstream hub, after
which a USB bus reset is expected. During this reset, TetraHub
initiates a chirp to indicate that it is a high speed peripheral. In a
USB 2.0 system, the upstream hub responds with a chirp
sequence, and TetraHub is in a high speed mode, with the
upstream D+ pull up resistor turned off. In USB 1.x systems, no
such chirp sequence from the upstream hub is seen, and
TetraHub operates as a normal 1.x hub (operating at full speed).
Enumeration
After a USB Bus Reset, TetraHub is in an unaddressed, uncon-
figured state (configuration value set to 0). During the enumer-
ation process, the host sets the hub's address and configuration
by sending a SetCongfiguration request. Changing the hub
address restores it to an unconfigured state.
For high speed multi-TT support, the host must also set the
alternate interface setting to 1 (the default mode is single TT).
After the hub is configured, the full hub functionality is available.
Multiple Transaction Translator Support
After TetraHub is configured in a high speed system, it is in single
TT mode. The host may then set the hub into multiple TT mode
by sending a SetInterface command. In multiple TT mode, each
full speed port is handled independently and thus has a full
12 Mbps bandwidth available. In Single TT mode, all traffic from
the host destined for full or low speed ports are forwarded to all
of those ports. This means that the 12 Mbps bandwidth is shared
by all full and low speed ports.
Downstream Ports
TetraHub supports a maximum of four downstream ports, each
of which may be marked as usable or removable in the extended
configuration (0xD2 EEPROM load, see section). Downstream
D+ and D– pull down resistors are incorporated in TetraHub for
each port. Prior to the hub being configured, the ports are driven
SE0 (Single Ended Zero, where both D+ and D– are driven low)
and are set to the unpowered state.
Document #: 38-08019 Rev. *M
on page 12 for more details.
Config-
After the hub is configured, the ports are not driven, and the host
may power the ports by sending a SetPortPower command to
each port. After a port is powered, any connect or disconnect
event is detected by the hub. Any change in the port state is
reported by the hub back to the host through the Status Change
Endpoint (endpoint 1). Upon receipt of SetPortReset command
from the host, the hub does the following:
■
■
■
■
Babble consists of either unterminated traffic from a downstream
port (or loss of activity), or a non-idle condition on the port after
EOF2. If babble is detected on an enabled port, that port is
disabled. A ClearPortEnable command from the host also
disables the specified port.
Downstream ports can be individually suspended by the host
with the SetPortSuspend command. If the hub is not suspended,
any resume will be confined to that individual port and reflected
to the host through a port change indication in the Hub Status
Change Endpoint. If the hub is suspended, a resume on this port
will be forwarded to the host, but other resume events will not be
seen on that port. The host may resume the port by sending a
ClearPortSuspend command.
Upstream Port
The upstream port includes the transmitter and the receiver state
machine. The transmitter and receiver operate in high speed and
full speed depending on the current hub configuration.
The transmitter state machine monitors the upstream facing port
while the hub repeater has connectivity in the upstream direction.
This monitoring activity prevents propagation of erroneous
indications in the upstream direction. In particular, this machine
prevents babble and disconnect events on the downstream
facing ports of this hub from propagating and causing the hub to
be disabled or disconnected by the hub to which it is attached.
This enables the hub to only disconnect the offensive port on
detecting a babble from it.
Power Switching
TetraHub includes interface signals for external port power
switches. Both ganged and individual (for each port) configura-
tions are supported, with individual switching being the default.
Initially all ports are unpowered. After enumerating, the host may
power each port by sending a SetPortPower command for that
port. The power switching and overcurrent detection of
downstream ports is managed by control pins connected to an
external power switch device. PWR [n]# output pins of the
CY7C65640A series are connected to the respective external
power switch's port power enable signals. (Note that each port
power output pin of the external power switch must be bypassed
with an electrolytic or tantalum capacitor as required by the USB
specification. These capacitors supply the inrush currents, which
occur during downstream device hot-attach events.)
Drive SE0 on the corresponding port
Put the port in an enabled state
Enable the green port indicator for that port (if not previously
overridden by the host)
Enable babble detection after the port is enabled.
CY7C65640A
Page 4 of 24
[+] Feedback