CY7C65621/31
Document #: 001-52934 Rev. **
Page 5 of 24
The LED control lines can also be modulated with a square wave
for power conservation. The polarity of these pins is program-
mable, see 0xD4 Load on page 13.
In manual mode, the indicators are under the control of the host,
which can turn on the LEDs, or leave them off. This is done by a
USB hub class request. Blinking of the LEDs is supported in
manual mode. The port indicators allow the user to intervene in
any error detection. For example, when babble is detected while
plugging in a defective device, or when an overcurrent condition
occurs, the port indicators corresponding to the downstream port
blink green or only light the amber LED, respectively.
Table 2 displays the color definition of the indicators when
CY7C65621/31 is in manual mode.[1]
Table 1. Automatic Port State to Port Indicator Color Mapping
Downstream Facing Hub Port State
Powered Off
Disconnected, Disabled,
Not Configured, Resetting, Testing
Enabled, Transmit, or
TransmitR
Suspended, Resuming,
SendEOR, Restart_E/S
Off or Amber, if due to an
Overcurrent Condition
Off
Green
Off
Note
1. Information presented in Table 1 and Table 2 is from USB 2.0 Specification Tables 11-6 and 11-7, respectively.
Table 2. Port Indicator Color Definitions in Manual Mode
Color Definition
Port State
Off
Not Operational
Amber
Error Condition
Green
Fully Operational
Blinking Off/Green
Software Attention
Blinking Off/Amber
Hardware Attention
Blinking Green/Amber
Reserved
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