4-Port USB2.0 Controller

Datasheet

SMSC USB20H04

Page 27

Revision 1.63 (10-14-04)

DATASHEET

Table 8.6 - Default Configuration Values

REGISTER

ADDRESS

REGISTER NAME

SELF-POWERED

DEFAULT (HEX)

BUS-POWERED

DEFAULT (HEX)

01h

VID MSB

04

04

02h

VID LSB

24

24

03h

PID MSB

**

**

04h

PID LSB

00

00

05h

DID MSB

00

00

06h

DID LSB

00

00

07h

Config Data Byte 3

58

98

08h

Config Data Byte 2

00

08

09h

Config Data Byte 1

05

05

0Ah

Max Power

00

64

0Bh

Hub Controller Max Current

00

64

0Ch

Power-on Time

80

80

** The default PID value is dependent on the silicon revision.

8.4

Reset

There are two different resets that the USB20H04 will experience. One is a hardware reset (via the

RESET_N pin) and the second a USB Reset.

8.4.1

External Hardware Reset

A valid hardware reset is initiated by the assertion of RESET_N for a minimum of 100ns after all power

supplies are within operating range.

Assertion of RESET_N (external pin) causes the following:

1.

2.

The PHYs are disabled, and the differential pairs will be in a high-impedance state

3.

All transactions immediately terminate, and no states are saved.

4.

All internal registers return to the default state (in most cases, 00(h)).

5.

LED indicators are disabled

After RESET_N is negated, the USB20H04 is ready to be configured as an SMBus slave (if SMB_SEL_N

= 0) or it reads OEM specific data from the external EEPROM (if SMB_SEL_N = 1). Default values for

configuration data are loaded if the SELF ONLY default strapping option is selected, or if an EEPROM is

not present. The timing associated with these options is shown in the tables below.