Port Indicators
The USB 2.0 port indicators are also supported directly by
CY7C65620/CY7C65630. According to the specification, each
downstream port of the hub optionally supports a status
indicator. The presence of indicators for downstream facing ports
is specified by bit 7 of the wHubCharacteristics field of the hub
class descriptor. The default CY7C65620/CY7C65630
descriptor specifies that port indicators are supported
(wHubCharacteristics, bit 7 is set). If port indicators are not
included in the hub, disable this bit through EEPROM settings.
Each port indicator pin is strategically located directly on the
opposite edge of the port with which it is associated. A port
indicator provides two colors: green and amber. This is usually
implemented as two separate LEDs, one amber and the other
green. A combination of hardware and software control is used
to inform the user of the current status of the port or the device
attached to the port and to guide the user through problem
resolution. Colors and blinking provide information to the user.
The significance of the color of the LED depends on the
operational mode of CY7C65620/CY7C65630. The
CY7C65620/CY7C65630 port indicators has two modes of
operation: automatic and manual.
On power up the CY7C65620/CY7C65630 defaults to automatic
mode, where the color of the Port Indicator (green, amber, off)
indicates the functional status of the CY7C65620/CY7C65630
port. In automatic mode, the CY7C65620/CY7C65630 turns on
the green LED whenever the port is enabled and the amber LED
when an overcurrent condition is detected. The color of the port
indicator is set by the port state machine. Blinking of the LEDs is
not supported in automatic mode. Table 1 identifies the mapping
of color to port state in automatic mode.