4-Port USB 2.0 Controller

Datasheet

SMSC USB20H04

Page 23

Revision 1.63 (03-30-07)

DATASHEET

BIT

FIELD NAME

DESCRIPTION

3:0

Port Non-Active

Selects which ports are active. A one indicates that the port is

non-active:

Bit 3: Port 4 is non-active.

Bit 2: Port 3 is non-active.

Bit 1: Port 2 is non-active.

Bit 0: Port 1 is non-active.

All zeroes sets all ports active.

Note: Active ports must be contiguous, and must start with port

number 1.

Table 8.4 - Address 8; Config_Byte_1

BIT

FIELD NAME

DESCRIPTION

7

Dynamic Power

Selects the ability to transition to bus-powered operation if the local

power source is removed:

0: No dynamic auto-switching.

1: Dynamic auto-switching ability enabled.

6

On-The-Go

Selects the ability to support an OTG host:

0: No OTG support.

1: OTG support enabled.

5:4

Reserved

Set to zero.

3:0

Over-Current Timer

Selects the over-current timer delay in 2 ms increments for the

active ports.

0101: delay is 2ms

1010: delay is 4ms

1111: delay is 6ms

Note: All other values are reserved

Table 8.5 - Addresses 9 - 11

BIT

FIELD NAME

DESCRIPTION

7:0

Max Power

Current in 2mA increments that the 4-port hub consumes from an

upstream port in this configuration.

A value of 50, or 32(h), indicates 100 mA.

7:0

HubContrCurrent

Absolute maximum current requirement in 2mA increments of the

hub controller electronics.

A value of 50, or 32(h), indicates 100 mA.

7:0

PwrOn2PwrGood

Time in 2ms intervals from the time the power on sequence begins

on a port until power is good on that port.

A value of 50, or 32(h), indicates 100 ms.

8.3

Default Configuration Values

Default values for configuration data are loaded as described in section 8.1.2 and 8.1.3 above. The values

programmed are summarized in Table 8.6 - Default Configuration Values.