Ultra Fast USB 2.0 Multi-Format Flash Media Controller/USB Hub Combo

 

 

 

BIT

 

 

NUMBER

BIT NAME

DESCRIPTION

 

 

 

5

HS_DISABLE

Hi-Speed Disable: Disables the capability to attach as either a Hi-/Full-Speed

 

 

device, and forces attachment as Full-Speed only (i.e. no Hi-Speed support).

 

 

0 = Hi-/Full-Speed

 

 

1 = Full-Speed-Only (Hi-Speed disabled!)

 

 

 

4

Reserved

Always reads ‘0’.

 

 

 

3

EOP_DISABLE

EOP Disable: Disables EOP generation of EOF1 when in Full-Speed mode.

 

 

During FS operation only, this permits the hub to send EOP if no

 

 

downstream traffic is detected at EOF1. See Section 11.3.1 of the USB 2.0

 

 

Specification for additional details. Note: generation of an EOP at the EOF1

 

 

point may prevent a Host Controller (operating in FS mode) from placing the

 

 

USB bus in suspend.

 

 

0 = An EOP is generated at the EOF1 point if no traffic is detected.

 

 

1 = EOP generation at EOF1 is disabled (Note: This is normal USB

 

 

operation).

 

 

Note: This is a rarely used feature in the PC environment, existing drivers

 

 

may not have been thoroughly debugged with this feature enabled.

 

 

It is included because it is a permitted feature in Chapter 11 of the

 

 

USB specification.

 

 

 

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 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

 

 

 

7.3.3.18E5h: Config Data Byte 2 (CFG_DAT_BYT2)

BIT

 

 

 

NUMBER

BIT NAME

 

DESCRIPTION

 

 

 

7:6

Reserved

Always reads ‘0’.

 

 

 

5:4

OC_TIMER

OverCurrent Timer: Over-current Timer delay.

 

 

00

= 50 ns

 

 

01

= 100 ns

 

 

10

= 200 ns

 

 

11 = 400 ns

 

 

 

 

Revision 2.0 (10-03-08)

38

SMSC USB2640/USB2641

 

DATASHEET