AT43USB320A_04 ATMEL [ATMEL Corporation], AT43USB320A_04 Datasheet - Page 88

• Manufacturer Part Number: AT43USB320A_04
• Description: Full-speed USB Microcontroller with an Embedded Hub
• Manufacturer: ATMEL [ATMEL Corporation]

Hub Status Register
88
AT43USB320A
In the AT43USB320A overcurrent detection and port power switch control output processing is
done in firmware. The hardware is designed so that various types of hubs are possible just
through firmware modifications.
1. Hub local power status, bits 0 and 2, are optional features and apply to hubs that report
2. Hub overcurrent status, bits 1 and 3, apply to self powered hubs with bus powered SIE
The firmware uses bits 1 and 3 to generate bit 0 of the Hub and Port Status Change Bitmap
which is transmitted through the Hub Endpoint1 Data Register. Bit 0 of this register is a 1
whenever bit 1 or 3 of HSTATR is a 1.
Hub Status Register – HSTR
• Bit 7..4 – Reserved
These bits are reserved in the AT43USB320A and will read as zero.
• Bit 3 – OVLSC: Overcurrent Status Change
0 = No change has occurred on Overcurrent Indicator
1 = Overcurrent Indicator has changed
• Bit 2 – LPSC: Hub Local Power Status Change
0 = No change has occurred on Local Power Status
1 = Local Power Status has changed
• Bit 1 – OVI: Overcurrent Indicator
0 = All power operations normal
1 = An overcurrent exist on a hub wide basis
• Bit 0 – LPS: Hub Local Power Status
0 = Local power supply is good
1 = Local power supply is lost (inactive)
Initial Value
Read/Write
$1FC7
on a global basis. If this feature is not used, both these bits should be programmed to
0. To use this feature, the firmware needs to know the status of the local power supply,
which requires an input pin and extra internal or external circuitry.
only, or hubs that are programmable as self/bus powered. The firmware should clear
these two bits to 0.
Bit
R
7
–
0
R
6
–
0
R
5
–
0
R
4
–
0
OVLSC
R/W
3
0
LPSC
R/W
2
0
R/W
OVI
1
0
LPS
R/W
1443E–USB–4/04
0
0
HSTR