T0044-03

0

0

1

1

1

1

1

1

2

56

57

58

SDATA

FOUT

EnterRegister

Read-BackMode

Fetch

EEPROM

ContentWith

1 CLK

st

EEPROMContent

1 Bit Available After

1 FallingEdge

st

st

60 FallingEdge

SwitchesBackInto

NormalOperation

th

OutputOscillation

OutputOscillation

REGISTER DESCRIPTIONS

CDCE421

In the following table, the content of the output bit stream is summarized. Important to notice: bit 0 is clocked out

first. The default values in register 0 to register 5 are programmed in the EEPROM.

OUTPUT BIT STREAM

FUNCTION

Bits[0:2]

Revision identifier (MSB first)

Bits[3:8]

VCO calibration word

Bit[9]

EEPROM status:

0 = EEPROM has never been written

1 = EEPROM has been programmed before

Bit[10]

EEPROM lock:

0 = EEPROM can be rewritten

1 = EEPROM is locked, rewriting to the EEPROM is not possible any more

Bits[11:18]

Storage value, Word5 (MSB first)

Bits[19:26]

Storage value, Word4 (MSB first)

Bits[27:34]

Storage value, Word3 (MSB first)

Bits[35:42]

Storage value, Word2 (MSB first)

Bits[43:50]

Storage value, Word1 (MSB first)

Bits[51:58]

Storage value, Word0 (MSB first)

Word 0:

DEFAULT

BIT

NAME

DESCRIPTION/FUNCTION

TYPE

VALUE

0

C0

Register selection

W

0

1

C1

Register selection

W

0

2

C2

Register selection

W

0

3

SELVCO

VCO select, 0 = VCO1, 1 = VCO2

W

0

4

SELPRESC

Prescaler setting, bit 0

W

0

5

SELPRESC

Prescaler setting, bit 1

W

1

6

OUTSEL

Output divider select, bit 0

W

1

7

OUTSEL

Output divider select, bit1

W

1

8

OUTSEL

Output divider select, bit 2

W

0

9

DRVSEL

Driver select, 0 = LVDS, 1 = PECL

W

1

10

TITEST0

Reserved

W

1

4

Divide by value (SELPRESC 1, SELPRESC 0)

Divide by 5 = (00), 3 = (01), 4 = (10), 2 = (11)

5

6

Output divider (OUTSEL2, OUTSEL1, OUTSEL0)

Divide by 1 = (000), 2 = (001), 4 = (010), 8 = (011), 16 = (100), 32 = (101)

7

8

8

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Product Folder Link(s): CDCE421