OFFSET
FIELD
bPwrOn2PwrGood
PROGRAMMABLE
SIZE
1
DESCRIPTION
5
Time (in 2 ms intervals) from the time power on
sequence begins on a port until power is good
on that port. System software uses this value
to determine how long to wait before accessing
a powered-on port.
6
7
bHubContrCurrent
DeviceRemovable
1
Maximum current requirements of the hub
controller electronics in mA.
X
Variable
depending
on number
of ports on
hub
Indicates if a port has a removable device
attached.
If a non-removable device is
attached to a port, that port will never receive
an insertion change notification. This field is
reported on byte-granularity. Within a byte, if
no port exists for a given location, the field
representing the port characteristics returns “0”.
Bit definition:
0 - Device is removable
1 - Device is not removable (permanently
attached)
This is a bitmap corresponding to the individual
ports on the hub:
Bit 0: Reserved for future use
Bit 1: Port 1
Bit 2: Port 2
Etc.
Bit n: Port n (implementation dependent, up to
a maximum of 255 ports).
Variable PortPwrCtrlMask
X
Variable
depending
on number
of ports on
hub
Indicates if a port is not affected by a gang-
mode power control request. Ports that have
this field set always require
a
manual
SetPortFeature(PORT_POWER) request to
control the port’s power state.
Bit definition:
0 - Port does not mask the gang-mode power
control capability.
1 - Port is not affected by gang-mode power
commands. Manual commands must be sent
to this port to turn power on and off. This is a
bitmap corresponding to the individual ports on
the hub:
Bit 0: Reserved for future use.
Bit 1: Port 1
Bit 2: Port 2
Etc.
Bit n: Port n (implementation dependent, up to
a maximum of 255 ports).
6.5 FLOPPY DISK CONTROLLER
The Floppy Disk controller (FDC) provides the interface between a host microprocessor and the floppy disk drives.
The FDC integrates the functions of the Formatter/Controller, Digital data Separator, Write Precompensation and
Data Rate Selection logic for an IBM XT/AT compatible FDC. The true CMOS 765B core guarantees 100% IBM PC
XT/AT compatibility in addition to providing data overflow and underflow protection.
The FDC is compatible to the 82077AA using SMSC's proprietary floppy disk controller core.
SMSC DS – LPC47M14X
Page 26
Rev. 03/19/2001
SMSC [ SMSC CORPORATION ]
