AT43USB355M-AC ATMEL [ATMEL Corporation], AT43USB355M-AC Datasheet - Page 97

• Manufacturer Part Number: AT43USB355M-AC
• Description: Full-speed USB Microcontroller with Embedded Hub, ADC and PWM
• Manufacturer: ATMEL [ATMEL Corporation]

2603G–USB–04/06
Hub Port Status Change Register – PSCR1..3
The microcontroller firmware uses the bits in this register to monitor when a port status change
has occurred, which then gets reported to the host through the Port Change Field
wPortChange.
Except for bit 3, the Port Overcurrent Indicator Change, the bits in this register are set by the
USB hardware. Otherwise, the firmware should only clear these bits.
• Bit 7..5 – Reserved
These bits are reserved in the AT43USB355 and will read as zero.
• Bit 4 – RSTSC: Port Reset Status Change
0 = No change
1 = Reset complete
This bit is set by the USB hardware after it completes RESET signaling which is initiated when
the Reset and Enable Port command is detected at the Port Control Register, HPCON. The
firmware sends this command when it decodes a SetPortFeature(PORT_RESET) request
from the host.
At EOF2 after the hardware completes the port reset, the hardware sets the Port Enable Sta-
tus bit and clears the Port Reset Status bit of the Hub Port Status Register, HPSTAT. Cleared
by firmware, ClearPortFeature(PORT_RESET).
• Bit 3 – POCIC: Port Overcurrent Indicator Change
0 = No change has occurred on Overcurrent Indicator
1 = Overcurrent Indicator has changed
This bit is relevant to hubs with individual overcurrent reporting only. The firmware sets this bit
as a result of detecting overcurrent at the ports OVC# pin. The firmware clears bit through
ClearPortFeature(PORT_OVER_CURRENT). For Port 1, this bit is always cleared.
• Bit 2 – PSSC: Port Suspend Status Change
0 = No change
1 = Resume completed
Port 2, 3 set by hardware upon completion of firmware initiated resume process. Port 1 set by
firmware 20 ms after the next EOF2 after completion of resume process. RESUME signaling is
initiated through global resume, selective resume and remote wakeup. Cleared by firmware
via host request ClearPortFeature(PORT_SUSPEND).
• Bit 1 – PESC: Port Enable/Disable Status Change
0 = No change has occurred on Port Enable/Disable Status
1 = Port Enable/Disable status has changed
Port1 $1FB0
Port2 $1FB1
Port3 $1FB2
Initial Value
Read/Write
Bit
R
7
–
–
–
0
R
6
–
–
–
0
R
5
–
–
–
0
RSTSC
RSTSC
RSTSC
R
4
0
POCIC
POCIC
POCIC
R
3
0
PSSC
PSSC
PSSC
R
2
0
AT43USB355
PESC
PESC
PESC
R
1
0
PCSC
PCSC
PCSC
R
0
0
PSCR1
PSCR2
PSCR3
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