Datasheet

High-Speed Inter-Chip (HSIC) USB 2.0 Hub and Flash Media Controller
Datasheet
Revision 1.3 (03-13-13) 38 SMSC USB4640/USB4640i
DATASHEET
4.4.4.8 E5h: Configuration Data Byte 2 (CFG_DAT_BYT2)
2:1 CURRENT_SNS Over-Current Sense
Selects current sensing on a port-by-port basis, all ports ganged, or none
(only for bus-powered hubs). The ability to support current sensing on a per
port or ganged basis is dependent upon the hardware implementation.
00 : Ganged sensing (all ports together)
01 : individual (port-by-port)
1x : over-current sensing not supported (must only be used with bus-
powered configurations)
0 PORT_PWR Port Power Switching
Enables power switching on all ports simultaneously (ganged), or port power
is individually switched on and off on a port-by-port basis (individual). The
ability to support power enabling on a port or ganged basis is dependent
upon the hardware implementation.
0 : ganged switching (all ports together)
1 : individual port-by-port switching
BIT NAME DESCRIPTION
7:6 rsvd
5:4 OC_TIMER OverCurrent Timer: over-current timer delay
00 : 50 ns
01 : 100 ns
10 : 200 ns
11 : 400 ns
3 COMPOUND Compound Device: allows OEM to indicate that the hub is part of a
compound device (per the USB 2.0 Specification). The applicable port(s)
must also be defined as having a “non-removable device”.
When configured via strapping options, declaring a port as non-removable
automatically causes the hub controller to report that it is part of a compound
device.
0 : no
1 : yes, the hub is part of a compound device
2:0 rsvd
BIT NAME DESCRIPTION