3

02/16/2012

PI6C49014

Networking Clock Generator

Serial Data Interface (SMBus)

PI6C49014isaslaveonlySMBusdevicethatsupportsindexedblockreadandindexedblockwriteprotocolusingasingle7-bitad-

dressandread/writebitasshownbelow.

Address Assignment

A6

A5

A4

A3

A2

A1

A0

R/W

1

1

0

1

0

0

1

0/1

How to Write

1 bit

8 bits

1

8 bits

1

8 bits

1

8 bits

1

8 bits

1

1 bit

Start

bit

d2H

Ack

Register

offset

Ack

Byte

Count = N

Ack

Data Byte

0

Ack

…

Data Byte

N - 1

Ack

Stop

bit

Note:

1.

Register offset for indicating the starting register for indexed block write and indexed block read. Byte Count in write mode cannot be 0.

Byte 0: Spread Spectrum Control Register

Bit

Description

Type

Power Up

Condition

Output(s)

Affected

Notes

7

SpreadSpectrumSelectionfor200MHzHCSL

PCI-Expressclocks

RW

0

200MHzHCSLPCI

Expressoutput

0=spreadoff

1=-0.5%down

spread

6

EnableshardwareorsoftwarecontrolofOEbits

(seeByte0–Bit6andBit5Functionalitytable)

RW

0

PD_RESETpin,

bit5

0=hardwarecntl

1=softwarectrl

5

SoftwarePD_RESETbit.Enablesordisablesall

outputs

(seeByte0–Bit6andBit5Functionalitytable)

RW

1

Alloutputs

0=disabled

1=enabled

4to1 Reserved

RW

Undefined

NotApplicable

0

OEforsingle-ended25MHzoutput25M_Out2

RW

1

Single-ended

25MHzoutput

25M_Out2

0=disabled

1=enabled

How to Read (M:abbreviationforMasterorController;S:abbreviationforslave/clock)

1 bit

8

bits

1 bit

8

bits

1 bit

1 bit

8

bits

1 bit

8

bits

1 bit

8

bits

1 bit

…

8

bits

1 bit

1 bit

M:

Start

bit

M:

Send

"D2h"

S:

sends

Ack

M:

send

start-

ing

data-

byte

loca-

tion:

N

S:

sends

Ack

M:

Start

bit

M:

Send

"D3h"

S:

sends

Ack

S:

sends

#of

data

bytes

that

will

be

sent:

X

M:

sends

Ack

S:

sends

start-

ing

data

byte

N

M:

sends

Ack

…

S:

sends

data

byte

N+X-

1

M:Not

Ac-

knowl-

edge

M:

Stop

bit

11-0146