TUSB8040

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SLLSE42F

– SEPTEMBER 2010 – REVISED OCTOBER 2011

3.3.8

Device Removable Configuration Register

Table 3-16. Register Offset 7h

BIT NO.

7

6

5

4

3

2

1

0

RESET STATE

0

0

0

0

0

0

0

0

Table 3-17. Bit Descriptions

– Device Removable Configuration Register

BIT

FIELD NAME

ACCESS

DESCRIPTION

7:4

RSVD

RO

Reserved. Read only, returns 0 when read.

Removable. The bits in this field indicate whether a device attached to downstream ports 3

through 0 are removable or permanently attached. A value of 0 indicates the device

attached to the port is not removable. A value of 1 indicates the device attached to the port

is removable.

Each bit corresponds directly to a downstream port, i.e. rmbl0 corresponds to downstream

port 0.

For the TUSB8040PFP:

The default value for these bits are loaded at the de-assertion of reset with the value of

3:0

rmbl[3:0]

RW

Four-port hub - rmbl[3:0] defaults to 1111b.

For the TUSB8040RKM:

The default value for these bits are loaded at the de-assertion of reset with the value of

LEDA[3:0]z_RMBL[3:0]:

Four-port hub - rmbl[3:0] defaults to wxyzb,

where w is LEDA3z_RMBL3, x is LEDA2z_RMBL2, y is LEDA1z_RMBL1 and z is

LEDA0z_RMBL0.

rmbl[3:0] may be over-written by EEPROM contents or by an SMBus host.

3.3.9

Port Used Configuration Register

Table 3-18. Register Offset 8h

BIT NO.

7

6

5

4

3

2

1

0

RESET STATE

0

0

0

0

0

0

0

0

Table 3-19. Bit Descriptions

– Port Used Configuration Register

BIT

FIELD NAME

ACCESS

DESCRIPTION

7:4

RSVD

RO

Reserved. Read only, returns 0 when read.

Used. The bits in this field indicate whether downstream ports 3 through 0 are enabled or

disabled for use. A value of 0 indicates the port is not used. A value of 1 indicates the port

is used.

Each bit corresponds directly to a downstream port, i.e. used0 corresponds to downstream

port 0.

For the TUSB8040PFP:

The default value for these bits are loaded at the de-assertion of reset with the value of

Four-port hub - used[3:0] defaults to 1111b.

3:0

used3:0]

RW

For the TUSB8040RKM:

The default value for these bits are loaded at the de-assertion of reset with the value of

LEDG[3:0]z_USED[3:0]:

Four-port hub - used[3:0] defaults to wxyzb,

where w is LEDG3z_USED3, x is LEDG2z_USED2, y is LEDG1z_USED1 and z is

LEDG0z_USED0.

used[3:0] may be over-written by EEPROM contents or by an SMBus host.

Copyright

© 2010–2011, Texas Instruments Incorporated

FUNCTIONAL DESCRIPTION

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