Module regs Copy item path Source Hcbulkcurrented Contains the physical address of the current endpoint descriptor of the bulk list Hcbulkheaded Contains the physical address of the first endpoint descriptor of the bulk list Hccommandstatus This register is used to receive the commands from the Host Controller Driver (HCD) Hccontrol Defines the operating modes of the HC Hccontrolcurrented Contains the physical address of the current endpoint descriptor of the control list Hccontrolheaded Contains the physical address of the first endpoint descriptor of the control list Hcdonehead Contains the physical address of the last transfer descriptor added to the ‘Done’ queue Hcfminterval Defines the bit time interval in a frame and the full speed maximum packet size which would not cause an overrun Hcfmnumber Contains a 16-bit counter and provides the timing reference among events happening in the HC and the HCD Hcfmremaining A 14-bit counter showing the bit time remaining in the current frame Hchcca Contains the physical address of the host controller communication area Hcinterruptdisable The bits in this register are used to disable corresponding bits in the HCInterruptStatus register and in turn disable that event leading to hardware interrupt Hcinterruptenable Controls the bits in the HcInterruptStatus register and indicates which events will generate a hardware interrupt Hcinterruptstatus Indicates the status on various events that cause hardware interrupts by setting the appropriate bits Hclsthreshold Contains 11-bit value which is used by the HC to determine whether to commit to transfer a maximum of 8-byte LS packet before EOF Hcperiodcurrented Contains the physical address of the current isochronous or interrupt endpoint descriptor Hcperiodicstart Contains a programmable 14-bit value which determines the earliest time HC should start processing a periodic list Hcrevision BCD representation of the version of the HCI specification that is implemented by the Host Controller (HC) Hcrhdescriptora First of the two registers which describes the characteristics of the root hub Hcrhdescriptorb Second of the two registers which describes the characteristics of the Root Hub Hcrhportstatus Controls and reports the port events on a per-port basis Hcrhstatus This register is divided into two parts Portmode Controls the port if it is attached to the host block or the device block