SBPH400-3 datasheet(27/43 Pages) STMICROELECTRONICS

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SBPH400-3

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Page_select

R/W

Select extended register page for a subsequent PHY register read or

write operation.

0 = Port Status Page

1 = Product Identification Page

Initialized to 0 on power reset.

Port_select

R/W

Identify the port for the selected register page for a subsequent PHY

defined in Table 2.17. For all other values, a subsequent write to any

rsv

R/W

Field reserved in P1394a for future use. No effect on write, always

reads as zero.

Table 2.17

Port status page

Address

01234

1000

AStat

BStat

Child

Con

Bias

Dis

1001

Negotiated_speed

Int_

enable

Fault

rsv

1010-1111

rsv

Table 2.18

Port status register fields

Field

Size

Type

Description

AStat

TPA line state on the selected port

(112 =Z, 012 = 1,102 =0,002 = invalid).

BStat

TPB line state on the selected port

(112 =Z, 012 = 1,102 =0,002 = invalid).

Child

If 1 the corresponding port is a child, else parent (only

valid after Self_ID)

Con

If 1 the corresponding port is connected, 0 if the port is

disconnected.

Bias

Reflects the Bias detected status on the port (1 = Bias

detected) after filtering

Dis

R/W

The port is disabled when this bit is set to 1, and

enabled when this bit is set to 0. Initialized to the value

of the PDISABLE pin on power reset.

Negotiated_speed

The negotiated speed for this port (only valid after

Self_ID). Possible values are 000b (S100), 001b

(S200), 010b (S400)

Table 2.16

SBPH400 register fields (continued)

Field

Size

Type

Description

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