RM0082
HS_USB2.0 host
Doc ID 018672 Rev 1
437/844
[07]
S
1’h0
Suspend.
This bit states whether the port is in suspend, according to
encoding:
1‘b0 = Port is not in suspend state.
1‘b1 = Port is in suspend state.
This S bit together with the port enabled bit (PEN) in this
register define the port states as follows:
1‘b0 1‘bx = Disabled.
1‘b1 1‘b0 = Enabled.
1‘b1 1‘b1 = Suspend.
When in suspend state, downstream propagation of data is
blocked on this port, except for port reset. The blocking occurs
at the end of the current transaction, if a transaction was in
progress when this bit was written to 1‘b1. In the suspend
state, the port is sensitive to resume detection. Note that the
bit status does not change until the port is suspended and that
there may be a delay in suspending a port if there is a
transaction currently in progress on the USB.
A write of 1’b0 to this bit is ignored by the EHCI Host
Controller. The EHCI host controller will unconditionally set
this bit to a zero when:
software sets the force port resume (FPR) bit to 1‘b0 (from a
1‘b1)
software sets the port reset (PR) bit to 1‘b1 (from a 1‘b0).
Note: If host software sets this bit to 1‘b1 when the port is not
enabled (i.e. PEN bit is 1‘b0) the results are undefined.
Note: This field is zero if port power (PP bit in this register) is
zero.
Table 362.
PORTSC register bit assignments (continued)
Bit
Name
Reset
value
Description