GL852 USB 2.0 MTT HUB Controller
5.2.6 Power Switch Enable Polarity (Not available for QFN 28 package)
Both low/high-enabled power switches are supported. It is determined by jumper setting, based on the state
of pin AMBER2, as the following table:
Table 5.2 – Configuration by power switch type
AMBER2
Power switch enable polarity
Low-active
0
1
High-active
5.2.7 Port number configuration (Not available for QFN 28 package)
Number of downstream port can be configured as 2/3/4 ports by pin strapping in addition to EEPROM,
based on the state of pin AMBER 3, AMBER 4, as the following table:
Table 5.3 – Port number configuration
AMBER3
AMBER 4
Port number
1
0
0
0
1
0
2
3
4
5.2.8 Non-removable port configuration (Not available for QFN 28 package)
For compound application or embedded system, downstream ports that always connected inside the system
can be set as non-removable based on the state of corresponding status LED, pin GREEN 1~4. If the pin is
pull high in the initial stage (POR reset), the corresponding port will be set as non-removable.
5.2.9 Reference clock configuration (Not available for QFN 28 package)
GL852 can support optional 27/48MHz clock source, which is selectable through GPIO configurations.
For some on-board design that 27/48MHz clock source is available, such as motherboard or Monitor
built-in applications, system integrator can leverage this feature to further reduce BOM cost by removing
external crystal.
Table 5.4 – Ref. Clock configuration
SEL48
SEL27
Clock source
48MHz OSC-in
0
1
1
1
0
1
27MHz OSC-in
12MHz X’tal/OSC-in
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