USB Host Controller
1554
SPNU503C – March 2018
Copyright © 2018, Texas Instruments Incorporated
Universal Serial Bus (USB)
Table 29-24. HC Port 0 Status and Control Register (HCRHPORTSTATUS0) Field Descriptions (continued)
Bit
Field
Value
Description
9
LSDA/CPP
Port 0 low-speed device attached/clear port power
This bit indicates, when read as 1, that a low-speed device is attached to port 0. A 0 in this bit
indicates a full-speed device.
This bit is valid only when port 0 current connect status is 1.
0
Write of 0 has no effect.
1
The host controller driver can write a 1 to this bit to clear the port 0 port power status.
8
PPS/SPP
Port 0 port power status/set port power
This bit indicates, when read as 1, that the port 0 power is enabled. When read as 0, port 0 power
is not enabled.
0
Write of 0 has no effect.
1
Write of 1 to this bit sets the port 0 port power status bit.
7-5
Reserved
0
Reserved
4
PRS/SPR
Port 0 port reset status/set port reset
When read as 1, indicates that port 0 is signaling the USB reset. When read as 0, USB reset is not
being sent to port 0.
0
Write of 0 has no effect.
1
Write of 1 to this bit sets the port 0 port reset status bit and causes the USB host controller to begin
signaling USB reset to port 0.
3
POCI/CSS
Port 0 port overcurrent indicator/clear suspend status
When read as 1, indicates a port 0 port overcurrent condition has occurred. When 0, no port 0 port
overcurrent condition has occurred.
0
Write of 0 has no effect.
1
Write of 1 to this bit when port 0 port suspend status is 1 causes resume signaling on port 0. A
write of 1 when port 0 port suspend status is 0 has no effect.
2
PSS/SPS
Port 0 port suspend status/set port suspend
When read as 0, indicates that port 0 is not in the USB suspend state. This bit is cleared
automatically at the end of the USB resume sequence and also at the end of the USB reset
sequence.
When read as 1, indicates that port 0 is in the USB suspend state or is in the resume sequence.
0
Write of 0 has no effect.
1
If port 0 current connect status is 1, a write of 1 to this bit sets the port 0 port suspend status bit
and places port 0 in USB suspend state. If current connect status is 0, a write of 1 instead sets
connect status change to inform the USB host controller driver software of an attempt to suspend a
disconnected device.
1
PES/SPE
Port 0 port enable status/set port enable
When read as 0, this bit indicates that port 0 is not enabled.
When read as 1, indicates that port 0 is enabled. This bit is automatically set at completion of port 0
USB reset if it was not already set before the USB reset completed, and is automatically set at the
end of a USB suspend if the port was not enabled when the USB resume completed.
0
Write of 0 has no effect.
1
Write of 1 to this bit when port 0 current connect status is 1 sets the port 0 port enable status bit. A
write of 1 when port 0 current connect status is 0 has no effect.
0
CCS/CPE
Port 0 current connection status/clear port enable
When read as 1, indicates that port 0 currently has a USB device attached. When 0, indicates that
no USB device is attached to port 0.
This bit is set to 1 after root hub reset if the HCRHDESCRIPTORB.DR[1] bit is set to indicate a
non-removable device on port 0.
0
Write of 0 has no effect.
1
Write of 1 to this bit clears the port 0 port enable bit.
