Description
This register is used as an offset to add to register base to find the beginning of the Operational Register Space.
Default value = 20h.
HCIVERSION – R - 16 bits - [MEM_Reg : 02h] Field Name Bits Default Description
HCIVERSION 15:0 0100h This is a two-byte register containing a BCD encoding of the
version number of interface to which this host controller
interface conforms.
Field Name Bits Default Description
N_PORTS 3:0 Ah This field specifies the number of physical downstream ports
implemented on this host controller. The value of this field
determines how many port registers are addressable in the
Operational Register Space. Valid values are in the range
of 1H to FH. A zero in this field is undefined.
Port Power Control (PPC) 4 0b This field indicates whether the host controller
implementation includes port power control. A one in this bit
indicates the ports have port power switches. A zero in this
bit indicates the port does not have port power switches.
The value of this field affects the functionality of the Port
Power field in each port status and control register.
Reserved 6:5 These bits are reserved and should be set to zero.
Port Routing Rules 7 0b This field indicates the method used by this implementation
for how all ports are mapped to companion controllers. The
value of this field has the following interpretation:
0 = The first N_PCC ports are routed to the lowest
numbered function companion host controller, the next
N_PCC port are routed to the next lowest function
companion controller, and so on.
1 = The port routing is explicitly enumerated by the first
N_PORTS elements of the HCSP-PORTROUTE array.
Number of Ports per
Companion Controller
(N_PCC)
11:8 2h This field indicates the number of ports supported per
companion host controller. It is used to indicate the port
routing configuration to system software. For example, if
N_PORTS has a value of 6 and N_CC has a value of 2 then
N_PCC could have a value of 3. The convention is that the
first N_PCC ports are assumed to be routed to companion
controller 1, the next N_PCC ports to companion controller
2, etc. In the previous example, the N_PCC could have
been 4, where the first 4 are routed to companion controller
1 and the last two are routed to companion controller 2. The
number in this field must be consistent with N_PORTS and
N_CC.
Number of Companion
Controller (N_CC)
15:12 5h This field indicates the number of companion controllers
associated with this USB 2.0 host controller. A zero in this
field indicates there are no companion host controllers.
Port-ownership hand-off is not supported. Only high-speed
devices are supported on the host controller root ports. A
value larger than zero in this field indicates there are
companion USB 1.1 host controller(s). Port-ownership
hand-offs are supported. High, Full- and Low-speed devices
are supported on the host controller root ports.
Port Indicators
(P_INDICATOR)
16 0b This bit indicates whether the ports support port indicator
control. When this bit is a one, the port status and control
registers include a read/writeable field for controlling the
state of the port indicator.