12

ICS1522

Memory Definition

ICS1522 memory is loaded serially with the least significant bit clocked into the device first. After the R/Wn bit, the next

three bits of the programming word (15 bits) hold the memory location to be loaded. The least significant 11 bits are the

data to be loaded (see Timing Diagram).

MEMORY

ADDRESS

DATA BITS

DEFAULT

VALUES

(HEX)

NAME

DESCRIPTION

000

0-10

04F

F(0:10)

Feedback Divider Modulus (Modulus = Value +1)

001

0-7

03

LO(0:7)

M Counter Lo Sync State

001

8-10

0

A

Don't Care

010

0-7

06

HI(0:7)

M Counter Hi Sync State

010

8-10

0

A

Don't Care

011

0-9

013

R(0:9)

Reference Divider Modulus (Modulus = Value + 1)

011

10

0

REF

POL External Reference Polarity (1 =Invert)

100

0-2

4

VCO(0:2)

VCO Gain

100

3-5

3

PFD(0:2)

Phase Detector Gain

100

6

1

PDEN

Phase Detector Enable (1 =Enable)

100

7

1

INT_FLT

Internal Loop Filter (1 = Internal)

100

8

1

INT_VCO

Internal VCO (1 = Internal)

100

9

0

CLK_SEL

Internal feedback input clock select

(0 = VCO Output)

100

10

1

Reserved

Reserved - Set to One

101

0

1

FBK_SEL

Feedback Select (1 =Internal)

101

1

0

FBK_POL

External Feedback Polarity (1 =Invert)

101

2

0

ADD

Addition of 1 VCO Cycle (0 to 1 = Add)

101

3

0

SWLW

Removal of 1 VCO Cycle (0 to 1 = Swallow)

101

4-5

0

PDA(0:1)

Output Post-Scaler

101

6-7

3

PDB(0:1)

Feedback Post-Scaler

101

8

1

LD_LG

Fine Phase Adj. Lead/Lag (1=Lead)

101

9

0

F_EN

Fine Phase Adj. Enable (1=Enable)

101

10

1

Reserved

Reserved - Set to One

110

0-2

7

L(0:2)

Load Counter

110

3

0

OMUX1

OUT1 Select (0 = Load Cntr, 1 = Div By 4 0Deg)

110

4

0

OMUX2

OUT2 Select (0 = Int Fbk, 1 = Div By 4 90Deg)

110

5

0

OMUX3

OUT3 Select (0 = Sync Lo, 1 = Div By 4 180Deg)

110

6

1

OMUX4

OUT4 Select (0 = Sync Hi, 1 = Div By 4 270Deg)

110

7

0

DACRST

Output Reset (CLK+ = 1, CLK- = 0)

110

8

0

AUXEN

Output Test Mode (1 = Test, See Board Test Support)

110

9

0

AUXCLK

Output Clock When in Test Mode

110

10

0

EXTREF

XTAL/EXTREF Input Buffer (1=EXTREF)