9DB833

EIGHT OUTPUT DIFFERENTIAL BUFFER FOR PCIE GEN1–3

IDT®

EIGHT OUTPUT DIFFERENTIAL BUFFER FOR PCIE GEN1–3

12

9DB833

MAY 25, 2018

SMBus Table: Frequency Select Register, READ/WRITE ADDRESS (Selectable)

Pin #

Name

Control Function

Type

0

1

Default

Bit 7

PD_Mode

PD# drive mode

RW

driven

Hi-Z

1

Bit 6

OE_Mode

OE#_Stop drive mode

RW

driven

Hi-Z

0

Bit 5

0

Bit 4

X

Bit 3

MODE1

BYPASS#/PLL1

RW

Latched

Bit 2

1

Bit 1

MODE0

BYPASS#/PLL0

RW

Latched

Bit 0

SRC_DIV#

SRC Divide by 2 Select

RW

x/2

x/1

1

SMBus Table: Output Control Register

Pin #

Name

Control Function

Type

0

1

Default

Bit 7

DIF_7

Output Enable

RW

Disable

Enable

1

Bit 6

DIF_6

Output Enable

RW

Disable

Enable

1

Bit 5

DIF_5

Output Enable

RW

Disable

Enable

1

Bit 4

DIF_4

Output Enable

RW

Disable

Enable

1

Bit 3

DIF_3

Output Enable

RW

Disable

Enable

1

Bit 2

DIF_2

Output Enable

RW

Disable

Enable

1

Bit 1

DIF_1

Output Enable

RW

Disable

Enable

1

Bit 0

DIF_0

Output Enable

RW

Disable

Enable

1

NOTE: The SMBus Output Enable Bit must be '1' AND the respective OE pin must be active for the output to run.

SMBus Table: OE Pin Control Register

Pin #

Name

Control Function

Type

0

1

Default

Bit 7

DIF_7

DIF_7 Stoppable with OE7#

RW

Free-run

Stoppable

0

Bit 6

DIF_6

DIF_6 Stoppable with OE6#

RW

Free-run

Stoppable

0

Bit 5

DIF_5

DIF_5 Stoppable with OE5#

RW

Free-run

Stoppable

0

Bit 4

DIF_4

DIF_4 Stoppable with OE4#

RW

Free-run

Stoppable

0

Bit 3

DIF_3

DIF_3 Stoppable with OE3#

RW

Free-run

Stoppable

0

Bit 2

DIF_2

DIF_2 Stoppable with OE2#

RW

Free-run

Stoppable

0

Bit 1

DIF_1

DIF_1 Stoppable with OE1#

RW

Free-run

Stoppable

0

Bit 0

DIF_0

DIF_0 Stoppable with OE0#

RW

Free-run

Stoppable

0

NOTE: If you wish the default to be "Stoppable" see the 9DB834.

SMBus Table: Reserved Register

Pin #

Name

Control Function

Type

0

1

Default

Bit 7

X

Bit 6

X

Bit 5

X

Bit 4

X

Bit 3

X

Bit 2

X

Bit 1

X

Bit 0

X

Reserved

Reserved

Reserved

See Operating Mode

Readback Table

See Operating Mode

Readback Table

Byte 0

-

-

-

-

-

-

-

-

16,17

30,29

20,21

34,33

30,29

20,21

16,17

12,13

8,9

Byte 2

42,41

38,37

34,33

12,13

8,9

Byte 3

Byte 1

42,41

38,37

Reserved

Reserved

Reserved

Reserved

Reserved

Reserved

Reserved

Reserved